U.  S.  DEPARTMENT   OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY— BULLETIN  NO.  80. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


PAPERS  ON  DECIDUOUS  FRUIT  INSECTS 
AND  INSECTICIDES. 


I.  THE  CODLING  MOTH  IN  THE  0ZARK3. 

By  E.  L.  JENNE,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

II.  THE  CIGAR  CASE-BEARER. 

By  A.  G.  HAMMAR,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

III.  ADDITIONAL  OBSERVATIONS  ON  THE  LESSER  APPLE  WORM. 

By  S.  W.  FOSTER  xsv  P.  R.  JONES,  Er.gaged  in  Deciduous  Fruit  Insect  Investigation*. 

IV.  THE  PEAR  THRIPS  AND  ITS  CONTROL. 

By  DUDLEY  MOULTON,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

V.  ON  THE  NUT-FEEDING  HABITS  OF  THE  CODLING  MOTH. 

By  S.  W.  FOSTER,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

VI  LIFE  HISTORY  OF  THE  CODLING  MOTH  IN  NORTHWESTERN  PENNSYLVANIA. 

By  A.  G.  HAMMAR,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

VII  (REVISED'.  THE  ONE-SPRAY  METHOD  IN  THE  CONTROL  OF  THE  CODLING 

MOTH  AND  THE  PLUM  CURCULIO. 

By  A.  L.  QUAINTANCE,  In  Charge  of  Deciduous  Fruit  Insect  Investigations, 

AND 

E.  L.  JENNE,  E.  W.  SCOTT,  and  R.  W.  BRAUCHER, 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

VIII.  TESTS  OP  SPRAYS  AGAINST  THE  EUROPEAN  FRUIT  LECANIUM  AND  THE 

EUROPEAN  PEAR  SCALE. 

By  P.  R.  JONES,  Engaged  in  Deciduous  FruitlnscctMunstigations. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1912. 


1 


U.  S.  DEPARTMENT  OF  AGRICULTURE, 

BUREAU  OF  ENTOMOLOGY— BULLETIN  NO.  80. 

L.  O.  HOWARD,  Entomologist  and  Chief  of  Bureau. 


PAPERS  ON  DECIDUOUS  FRUIT  INSECTS 
AND  INSECTICIDES 


I.  THE  CODLING  MOTH  IN  THE  OZARKS. 

By  E.  L.  JENNE,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

II.  THE  CIGAR  CASE-BEARER. 

By  A.  G.  HAMMAR,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

III.  ADDITIONAL  OBSERVATIONS  ON  THE  LESSER  APPLE  WORM. 

By  S.  W.  FOSTER  and  P.  R.  JONES,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

IV.  THE  PEAR  THRIPS  AND  ITS  CONTROL. 

By  DUDLEY  MOULTON,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

V.  ON  THE  NUT-FEEDING  HABITS  OF  THE  CODLING  MOTH. 

By  S.  W.  FOSTER,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

VI.  LIFE  HISTORY  OF  THE  CODLING  MOTH  IN  NORTHWESTERN  PENNSYLVANIA. 

By  A.  G.  HAMMAR,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 

VII  (REVISED).  THE  ONE-SPRAY  METHOD  IN  THE  CONTROL  OF  THE  CODLING 
MOTH  AND  THE  PLUM  CURCULIO. 

By  A.  L.  QUAINTANCE,  In  Charge  of  Deciduous  Fruit  Insect  Investigations, 

AND 

E.  L.  JENNE,  E.  W.  SCOTT,  and  R.  W.  BRAUCHER, 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

VIII.  TESTS  OF  SPRAYS  AGAINST  THE  EUROPEAN  FRUIT  LECANIUM  AND  THE 

EUROPEAN  PEAR  SCALE. 

By  P.  R.  JONES,  Engaged  in  Deciduous  Fruit  Insect  Investigations. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE. 

1912. 


B  UREA  U  OF  ENTOMOLOG  Y. 

L.  O.  Howard,  Entomologist  and  Chief  of  Bureau. 
C.  L.  Marlatt,  Entomologist  and  Acting  Chief  in  Absence  of  Chief. 
R.  S.  Clifton,  Executive  Assistant. 
W.  F.Tastet,  Chief  Clerk. 

F.  H.  Chittenden,  in  charge  of  truck  crop  and  stored  product  insect  investigations. 

A .  I ».  Hopkins,  in  charge  of  forest  insect  investigations. 

W.  D.  Hunter,  in  charge  of  southern  field  crop  insect  investigations. 

V.  M.  Webster,  in  charge  of  cereal  and  forage  insect  investigations. 

A  .  L.  Quaintance,  in  charge  of  deciduous  fruit  insect  investigations. 

E.  F.  Phillips,  in  charge  of  bee  culture. 

I ).  M .  Rogers,  in  charge  of  preventing  spread  of  moths,  field  work. 

Rolla  P.  Currie,  in  charge  of  editorial  vork. 

Mabel  Colcord,  in  charge  of  library. 

Deciduous  Fruit  Insect  Investigations. 

A.  L.  Quaintance,  in  charge. 

Prbd  Johnson,  E.  L.  Jenne,  P.  R.  Jones,  A.  G.  Hammar,  R.  A.  Cushman,  J.B. 
Gill,  R.  L.  Nougaret,  W.  M.  Davidson,  L.  L.  Scott,  F.  E.  Brooks,  W.  B.  Wood, 
E.  B.  Blakeslee,  E.  H.  Siegler,  A.  C.  Baker,  agents  and  experts. 

E.  W,  Scott,  F.  L.  Simanton,  J.  F.  Zimmer,  entomological  assistants. 

8.  W.  Foster,  W.  H.  Sill,  employed  in  enforcement  of  insecticide  act,  1910. 

n 


LETTER  OF  TRANSMITTAL 


U.  S.  Department  of  Agriculture, 

Bureau  of  Entomology, 
Washington,  D.  C,  November  20, 1911. 
Sir:  I  have  the  honor  to  transmit  herewith,  for  publication  as 
Bulletin  No.  80,  eight  papers  dealing  with  deciduous  fruit  insects 
and  insecticides.  These  papers,  which  were  issued  separately  during 
the  years  1909-10,  are  as  follows:  The  Codling  Moth  in  the  Ozarks, 
by  E.  L.  Jenne;  The  Cigar  Case-Bearer,  by  A.  G.  Ham  mar;  Addi- 
tional Observations  on  the  Lesser  Apple  Worm,  by  S.  W.  Foster  and 
P.  R.  Jones;  The  Pear  Thrips  and  Its  Control,  by  Dudley  Moulton; 
On  the  Nut-Feeding  Habits  of  the  Codling  Moth,  by  S.  W.  Foster; 
Life  History  of  the  Codling  Moth  in  Northwestern  Pennsylvania,  by 
A.  G.  Hammar;  The  One-Spray  Method  in  the  Control  of  the  Codling 
Moth  and  the  Plum  Curculio,  by  A.  L.  Quaintance,  E.  L.  Jenne, 
E.  W.  Scott,  and  R.  W.  Braucher;  Tests  of  Sprays  Against  the  Euro- 
pean Fruit  Lecanium  and  the  European  Pear  Scale,  by  P.  R.  Jones. 
Respectfully, 

L.  O.  Howard, 

Chief  of  Bureau. 
Hon.  James  Wilson, 

Secretary  of  Agriculture. 


in 


PREFACE. 


The  present  series  of  articles  on  deciduous  fruit  insects  and  insecti- 
cides, Parts  I  to  VIII,  comprises  Bulletin  80. 

The  first  article,  on  the  codling  moth  in  the  Ozarks,  is  a  report  on 
two  years'  study  of  the  fife  history  of  this  insect,  which  is  very 
destructive  in  that  locality.  For  the  first  time  three  generations  of 
larvae  have  definitely  been  established. 

The  cigar  case-bearer,  treated  in  the  second  paper,  is  an  insect 
that  periodically  attracts  attertion  by  reason  of  its  injuries.  During 
the  outbreak  of  this  species  in  the  general  region  of  North  East,  Pa., 
during  the  season  of  1908,  exceptional  opportunity  was  presented  for 
a  study  of  its  life  history  and  habits,  as  detailed  in  the  paper  in 
question. 

The  lesser  apple  worm  was  the  subject  of  an  article  issued  in  1908 
as  Part  V  of  Bulletin  68.  At  that  time  the  egg  had  not  been  found, 
and  there  was  question  whether  this  species  fed  to  any  extent  upon 
the  twigs  of  apple.  Further  observations  on  this  important  apple 
insect  are  presented  in  Part  III,  in  which  the  egg  stage  is  described, 
although  previously  noted  by  Mr.  E.  P.  Taylor,  and  it  was  also  found 
that  the  boring  of  apple  twigs  is  due  to  the  work  of  another  species. 

The  fourth  paper,  on  the  pear  thrips  and  its  control,  comprises  the 
second  report  upon  this  species,  which  is  so  destructive  to  deciduous 
fruits  in  the  San  Francisco  Bay  region  in  California.  The  first  paper, 
issued  as  Part  I  of  Bulletin  68,  contained  the  principal  facts  in  the 
life  history  of  the  insect,  which  are  repeated  and  extended  in  the 
present  paper,  with  the  addition  of  many  data  resulting  from  large- 
scale  experiments  with  remedies  in  orchards.  Practicable  control 
measures  are  indicated. 

The  feeding  of  the  codling  moth  upon  nuts  has  been  occasionally 
recorded  in  the  literature  of  this  insect,  although  the  evidence  has 
been  inconclusive,  and  it  was  the  consensus  of  opinion  among  ento- 
mologists that  the  insect  never  normally  fed  upon  nuts.  Part  V  of 
the  present  bulletin  details  definite  extended  observations  showing 
that  under  certain  conditions  in  California  the  codling  moth  is  a  seri- 
ous pest  in  its  work  on  English  or  Persian  walnuts. 

Part  VI,  which  deals  with  the  life  history  of  the  codling  moth  in 
northwestern  Pennsylvania,  follows  in  general  the  plan  of  treatment 
of  Part  I  of  this  bulletin,  and  constitutes  the  second  article  dealing 


VI  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 

with  the  detailed  life  history  of  this  insect  in  an  important  fruit 
region.  Similar  studies  are  under  way  or  planned  covering  the  prin- 
cipal fruit  sections  of  the  United  States.  A  report  will  shortly  be 
prepared  dealing  with  the  codling  moth  in  Michigan. 

During  the  past  few  years  there  lias  been  considerable  interest 
aroused,  following  the  experience  of  certain  western  entomologists 
and  orchardists,  in  the  practicability  of  controlling  the  codling  moth 
by  a  single  thorough  application  immediately  after  the  falling  of  the 
petals.  This  so-called  one-spray  method  has  been  compared  with 
the  usual  spraying  schedule  in  vogue  in  the  East  by  numerous  east- 
ern entomologists,  and  the  results  of  the  investigations  of  this 
bureau  on  the  relative  merits  of  these  two  spraying  methods  in  the 
control  of  the  codling  moth  and  also  in  the  control  of  the  plum 
curculio  are  detailed  in  Part  VII. 

The  final  paper,  Part  VIII,  reports  on  tests  of  sprays  against 
the  European  fruit  Lecanium  and  the  European  pear  scale,  two 
serious  scale-insect  enemies  of  deciduous  fruits  in  California. 

A.  L.  QUAINTANCE, 

In  Charge  of  Deciduous  Fruit  Insect  Investigations. 


CONTENTS.' 


Page. 

The  codling  moth  in  the  Ozarks E.  L.  Jenne. .  1 

Seasonal  history 1 

Spring  brood  of  pupae 1 

Spring  brood  of  moths 4 

The  first  generation 6 

The  second  generation 11 

The  third  generation 17 

Wintering  larvae 19 

Review  of  rearing  work  of  the  season 20 

Third  generation  in  1907 22 

Miscellaneous  observations 23 

Band  records 23 

Emergence  of  moths 26 

Larvae  on  foliage 27 

Larvae  in  peaches 28 

Numerous  larvae  in  one  apple 28 

Number  of  molts 29 

Natural  enemies 29 

Percentage  of  fruit  infested 30 

Conclusions 31 

The  cigar  case-bearer  (Coleophora  fletcherella  Fernald) A.  G.  Hammar. .  33 

History 33 

Distribution , 35 

Food  plants  and  injury 36 

Description 37 

Seasonal  history 39 

Enemies 41 

Methods  of  control. 41 

Bibliography 42 

Additional  observations  on  the  lesser  apple  worm  (Enarmonia  prunivora  Walsh), 

S.  W.  Foster  and  P.  R.  Jones 45 

Two  apple  caterpillars  other  than  the  codling  moth 46 

Comparative  abundance  of  the  lesser  apple  worm  and  codling  moth  in 

apples 46 

Seasonal  history  and  habits 47 

Life  cycle  and  duration  of  stages 48 

Description  of  egg 50 

Parasites 50 

Control  measures 50 

The  pear  thrips  and  its  control  (Euthrips  pyri  Daniel) Dudley  Moulton. .  51 

Distribution 51 

Character  of  injury 52 

Seasonal  history  and  habits 55 

Methods  of  treatment 60 

Summary 66 

1  The  eight  papers  constituting  this  bulletin  were  issued  in  separate  form  on  June  26  and  30,  Aug.  12,  and 
Sept.  1, 1909,  and  Sept.  20  and  Nov.  28, 1910  (three  papers  on  the  last  date).  Part  VII,  revised,  was  issued 
on  Mar.  30, 1911. 

vn 


VIII  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 

Page. 

On  the  nut-feeding  habits  of  the  codling  moth S.  W.  Foster. .  67 

Notice  of  walnut  infest;! t ion 67 

Nature  of  injury 68 

Extent  of  infestation 68 

Varieties  attacked 68 

Seasonal  history  of  the  codling  moth  on  walnuts 68 

Control 70 

Life  history  of  the  codling  moth  in  northwestern  Pennsylvania. -4.  G.  Hammar. .  71 

Seasonal-history  studies  of  1909 72 

Source  of  rearing  material 72 

Overwintering  larvae 72 

Spring  brood  of  pupae 73 

Spring  brood  of  moths 74 

The  first  generation 80 

The  second  generation 91 

Band  records  of  1909 95 

Review  of  the  life-history  work  of  1909 98 

Seasonal-history  studies  of  1907  and  1908 98 

Source  of  rearing  material 98 

Time  of  emergence  of  moths  of  the  spring  brood 100 

Time  of  emergence  of  moths  of  the  first  brood 100 

Band  records  of  1907  and  1908 102 

Weather  records  for  1907,  1908,  and  1909 104 

Comparative  life-history  studies  for  the  seasons  of  1907,  1908,  and  1909 108 

Insect  enemies 110 

Summary 110 

The  one-spray  method  in  the  control  of  the  codling  moth  and  the  plum  curculio, 

A.  L.  Quaintance,  E.  L.  Jenne,  E.  W.  Scott,  and R.  W.  Braucher 113 

Results  of  experiments  with  the  one-spray  method  as  compared  with  results 

from  the  usual  schedule  of  applications 116 

Experiments  in  Arkansas 116 

Experiments  in  Virginia 130 

W.  S.  Ballard's  orchard 130 

Orchard  of  Strathmore  Orchard  Co 134 

Experiments  in  Michigan 137 

Summary  statement  of  results 145 

Conclusions 146 

Tests  of  sprays  against  the  European  fruit  Lecanium  and  the  European  pear 

scale P.  R.  Jones. .  147 

The  European  fruit  Lecanium  (Lecanium  corni  Bouch6) 148 

Appearance  of  the  insect 148 

Plan  of  work  and  method  of  ascertaining  results 148 

Application  of  sprays 148 

Sprays  used  and  methods  of  preparation 148 

Results 151 

The  European  pear  scale  (Epidiaspis  pyricola  Del  Guer.) 151 

Appearance  of  the  insect  and  extent  of  injury 151 

Spraying  experiments  in  1908 152 

Spaying  experiments  in  1909 155 

1     i  of  spraying 158 

Summary 159 

Index 161 


ILLUSTRATIONS 


PLATES. 

Page. 
Plate  I.  The  cigar  case-bearer  (Coleophora  fietcherella).    Fig.  1.— Apple  leaf 
with  larvae  at  work.     Fig.  2. — Infested  apple  twig,  two  weeks  after 
larvae  ceased  feeding.     Fig.  3. — Young  branches  with  puncturelike 

feeding  marks  of  the  larvae 36 

II.  The  cigar  case-bearer.  Fig.  1. — Apple  leaf  from  which  numerous 
cases  have  been  constructed.  Fig.  2. — Over- wintering  larvae.  Fig. 
3. — Apple  leaf  from  which  cigar-shaped  cases  have  been  made;  the 
empty  spring  cases  still  adhering.  Fig.  4. — Newly  emerged  moths 
in  their  characteristic  pose  on  the  empty  cases 38 

III.  The  lesser  apple  worm  {Enarmonia  prunivora).     Fig.  1. — Photomi- 

crograph of  egg.     Fig.  2. — Work  of  larvae  on  fruit  of  Crataegus 48 

IV.  Condition  of  buds  at  the  time  when  first  spraying  for  the  pear  thrips 

(Euthrips  pyri)  should  be  given.     Fig  1. — Bartlett  pear.     Fig.  2. — 

French  prune.     Fig.  3. — Imperial  prune 54 

V.  Work  of  the  pear  thrips  on  pear.  Fig.  1. — Destruction  of  buds  and 
blossoms.     Fig.  2. — Scabbing  of  fruit  from  feeding  punctures  by 

adults  on  the  opening  buds  in  spring 54 

VI.  Work  of  the  pear  thrips  on  French  prune.  Fig.  1. — Shoot  on  which 
crop  has  been  largely  destroyed  in  blossom  stage.  Fig.  2. — Young 
fruit,  natural  size,  showing  scabbing  resulting  from  work  of  larvae. 
Fig.  3. — Mature  fruit,  showing  scabbing  injury,  resulting  in  a  low 

grade  of  dried  fruit 54 

VII.  Codling-moth  injury  to  French  walnuts.  Fig.  1. — Concord  variety 
of  French  walnut,  showing  character  of  injury  by  larvae  of  the  cod- 
ling moth.     Fig.  2. — Concord  variety  of  French  walnut,  about 

twice  natural  size,  showing  larva  at  work 68 

VIII.  Codling-moth  injury  to  French  walnuts.  Fig.  1. — Concord  variety 
of  French  walnut,  showing  fibrous  tissue  connecting  the  halves, 
and  empty  pupal  skin.  Fig.  2. — Concord  variety  of  French  wal- 
nut, showing  entrance  and  exit  holes  of  larva 68 

IX.  Portion  of  outdoor  shelter  used  in  rearing  the  codling  moth  in  1909, 

at  North  East,  Pa 72 

X.  Fig.  1. — View  in  orchard  of  Mrs.  S.  E.  Jones,  near  Siloam  Springs,  Ark. 

Fig.  2. — View  in  orchard  of  Mr.  W.  S.  Ballard,  near  Crozet,  Va 116 

XI.  Fig.  1. — View  in  orchard  of  the  Strathmore  Orchard  Co.,  near  Mount 
Jackson,  Va.     Fig.  2. — View  in  the  E.  H.  House  orchard,  near 

Saugatuck,  Mich 134 

XII.  Fig.  1. — The  European  fruit  Lecanium  {Lecanium  corni)  on  pecan. 

Fig.  2. — The  European  pear  scale  (Epidiaspis  pyricola)  on  pear 148 

XIII.  View  of  prune  orchard  used  in  experiments  against  the  European 

pear  scale 152 

IX 


X  DECIDUOUS  FRUIT   INSECTS  AND   INSECTICIDES. 

TEXT   P1GUBE8. 

Page. 

Vic.  1.  Curve  showing  emergence  of  spring  brood  of  adults  of  codling  moth 

(< Car pocapsa  pomonella)  from  collected  wintering  material 5 

'1.  Curve  showing  record  of  larvae  and  pupae  of  the  codling  moth  taken 

from  bands  in  1907 24 

3.  Curve  showing  band  record  of  1908 25 

•1.  Curve  showing  band  record  from  6  Jonathan  apple  trees,   made  at 

Anderson,  Mo.,  in  1908 25 

».  Curve  showing  band  record  from  14  Gano  and  Lansingburg  apple  trees, 

made  at  Anderson,  Mo. ,  in  1908 26 

G.  Curve  showing  emergence  of  adults  from  material  collected  in  taking 

band  record  in  1907 27 

7.  Curve  showing  emergence  of  adults  from  material  collected  in  taking 

band  record  in  1908 27 

8.  Diagram  illustrating  the  seasonal  history  of  the  codling  moth  as  ob- 

served in  1908  at  Siloam  Springs,  Ark 32 

9.  The  peculiar  cases  of  the  cigar  case-bearer  (Coleophora  Jletcherella) 37 

10.  The  cigar  case-bearer:  Adult  female,  egg,  larva,  pupa,  details 38 

11 .  Life  cycle  of  the  cigar  case-bearer 40 

12.  Habrocytus  sp.,  a  parasite  of  the  cigar  case-bearer 41 

13.  The  pear  thrips  (Euthrips  pyri):  Ovipositor  and  end  of  abdomen  from 

side 55 

14.  The  pear  thrips:  Eggs 57 

15.  The  pear  thrips :  Larva 58 

16.  The  pear  thrips:  Nymph  or  pupa 59 

17.  The  pear  thrips:  Adult 60 

18.  Rearing  device  for  pupal  records 72 

19.  Emergence  curve  of  spring-brood  moths,  1909 75 

20.  Emergence  curve  of  first-brood  moths,  1909 87 

21.  Band-record  curve  of  1909 96 

22.  Diagram  showing  the  seasonal  history  of  the  codling  moth  in  1909 99 

23.  Emergence  curve  of  spring-brood  moths,  1907 101 

24.  Emergence  curve  of  first-brood  moths,  1907 101 

25.  Emergence  curve  of  first-brood  moths,  1908 101 

26.  Band-record  curve  of  1907 103 

27.  Band-record  curves  of  1908 103 

28.  Maximum  and  minimum  temperature  curves,  1907 105 

29.  Maximum  and  minimum  temperature  curves,  1908 106 

30.  Maximum  and  minimum  temperature  curves,  1909 107 

31.  Time  of  emergence  of  spring-brood  and  first-brood  moths,  and  the 

blossom  periods  of  apple  trees,  during  1907,  1908,  and  1909 108 

32.  Time  of  leaving  the  fruit  of  the  first-brood  and  second-brood  larvae 

during  1907,  1908,  and  1909 109 

33.  The  condition  of  the  calyx  cup  of  the  apple  in  relation  to  spraying  for 

the  codling  moth 114 

34.  Diagram  of  the  Mrs.  S.  E.  Jones  orchard,  Siloam  Springs,  Ark.,  showing 

location  of  plats  and  trees  used  for  making  counts  of  fruit 117 

Diagram  showing  arrangement  of  plats  and  trees  in  the  W.  S.  Ballard 

orchard,  near  Crozet,  Ya 130 

:'.<;.    Diagram  showing  arrangement  of  plats  and  trees  in  the  orchard  of  the 

Strathmore  Orchard  Co.,  near  Mount  Jackson,  Ya 135 

Diagram  illustrating  arrangement  of  plats  and  position  of  trees  in  the 

E.  H.  House  orchard,  near  Saugatuck,  Mich 138 


U.  S.  D.  A.,  B.  E.  Bui.  80,  Part  I.  D.  F.  I.  L,  June  26,  1909. 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


THE  CODLING  MOTH  IN  THE  OZARKS. 

By  E.  L.  Jemnb, 

Engaged  in  Deciduous  Fruit  Insect  Investigations. 

In  1907  the  Bureau  of  Entomology  undertook  some  experimental 
and  demonstration  spraying  for  the  control  of  the  codling  moth  at 
Siloam  Springs,  Benton  County,  Arkansas.  The  work  being  largely 
investigation  of  remedies,  only  a  few  notes  relating  to  the  life  history 
of  the  insect  were  secured.  The  following  season  a  fuller  line  of 
rearing  work  was  conducted  at  the  same  place,  and  the  present 
account  of  the  codling  moth  in  that  locality  applies  mainly  to  the 
season  of  1908.  Data  for  1907  are  introduced  for  comparison,  where 
it  is  possible. 

In  1908  the  rearing  work  was  conducted  out  of  doors.  Moths 
were  confined  in  Riley  rearing  cages;  larvae  were  reared  in  fruit 
inclosed  in  paper  bags  on  the  trees,  or  in  picked  fruit  in  muslin- 
covered  battery  jars;  and  the  pupal  periods  were  observed  in  small 
vials. 

SEASONAL  HISTORY. 

SPRING   BROOD   OF   PUP^.a 

Duration  of  the  brood. — The  earliest  pupae  did  not  come  under 
observation,  but  judging  from  the  first  emergence  of  moths  and  the 
length  of  the  earliest  observed  spring  pupal  stages,  pupation  began 
in  late  February  or  early  March. 

«  The  term  "brood  "  is  used  in  speaking  of  any  single  stage  of  the  insect,  and  "gen- 
eration" to  include  all  the  stages  of  the  life  cycle. 

The  pupae  and  moths  produced  by  the  transformation  of  the  wintering  larvae  are 
sometimes  termed  "first-brood  pupa?"  and  "first-brood  moths."  Here,  however, 
the  first  generation  is  regarded  as  beginning  with  the  first  eggs  of  the  season,  and 
ending  with  the  moths  that  develop  therefrom.  Where  three  generations  of  the 
insect  occur,  the  adult  stages  are  spoken  of  as  moths  of  spring  brood,  moths  of  first 
brood,  and  moths  of  second  brood.  The  adults  of  the  third  generation  become  the 
spring  brood  of  moths  for  the  succeeding  year.  The  spring  moths  lay  the  first-brood 
eggs,  the  first-brood  moths  lay  the  eecond-brood  eggs,  and  second-brood  moths  lay 
the  third-brood  eggs. 

1 


2  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 

On  March  24  there  were  taken,  from  rubbish  on  the  ground  under 
an  outdoor  apple  bin  at  a  vinegar  factory,  6  pupae  and  130  larvae. 
They  were  located  in  a  damp  place,  shaded  during  the  greater  part 
of  the  day.  Above,  in  crevices  of  the  apple  bin,  were  many  cocoons, 
for  the  most  part  inaccessible,  but  those  that  could  be  examined 
showed  a  much  larger  proportion  of  pupae. 

On  March  31  some  timbers  were  pried  from  this  bin  and  larvae  and 
pupae  were  found  in  about  equal  numbers — 122  larvae  and  112  pupae. 
This  bin  was  situated  on  the  west  side  of  the  building  and  was  built 
of  2  by  4  material,  nailed,  1  inch  apart,  to  large  supporting  timbers. 
The  cocoons  occurred  between  the  scantlings  and  their  supports. 
This  should  represent  fairly  normal  conditions  above  ground.  Even 
here  pupae  would  be  found  greatly  in  the  majority  under  one  scant- 
ling, while  beneath  an  adjoining  one  nearly  all  cocoons  might  contain 
larvae.  This  was  evidently  due  to  the  fact  that  some  of  the  pine 
scantlings  were  sapwood,  which  absorbs  much  moisture  during  rains. 
At  the  time  of  examination  they  were  damp  and  soggy,  though  no 
rain  had  fallen  for  several  days.  Under  these  the  proportion  of 
pupae  was  much  smaller  than  under  dry  scantlings  adjoining. 

No  empty  pupal  cases  were  found  March  31,  although  one  adult 
moth,  evidently  just  emerged,  was  captured  while  sunning  itself  on 
the  bin.  On  April  21  the  bin  was  again  examined,  and  there  were 
found  79  larvae,  114  pupae,  and  64  empty  cases.  This  showed  that 
about  70  per  cent  of  the  wintering  larvae  had  pupated  up  to  that 
time.  But  even  yet  larvae  were  in  the  majority  in  damp  and  shaded 
parts. 

Nearly  all  of  the  larvae  collected  on  the  above  dates  and  kept  out 
of  doors  in  vials  had  pupated  by  May  12.  Two  belated  individuals 
pupated  May  19  and  20.  This  gives  a  probable  time  of  2\  months 
during  which  wintering  larvae  transformed  to  pupae.  Apple  trees 
bloomed  about  the  middle  of  this  period.  The  majority  of  the 
spring  pupae  had  given  out  adults  by  May  27,  the  two  belated  indi- 
viduals emerging  June  6  and  8.  Thus  there  is  a  period  of  about  3 
months  during  which  spring  pupae  were  present — from  the  first  of 
March  until  June. 

Length  of  spring  pupal  stage. — Individual  records  were  obtained  of 
131  spring  pupae,  from  larvae  collected  at  the  out  door  apple  bin. 
The  material  was  kept  out  of  doors  in  vials  in  a  pasteboard  box, 
under  as  nearly  a  normal  temperature  as  possible.  The  length  of  the 
pupal  stage  steadily  decreased  with  the  advancement  of  the  season. 
Doubtless  a  longer  period  would  have  been  shown  for  the  first  pupa 
of  the  season  if  they  could  have  been  observed. 

The  records  of  the  Bpring  pupal  stages  are  given  in  Tables  I  and  1 1, 
with  a  summary  in  Table  III. 


THE   CODLING   MOTH   IN   THE   OZARKS.  3 

Table  I.— Length  of  pupal  periods  in  spring  brood  of  pupae— from  wintering  larvae 

collected  March  31. 


Individual  No. 

Winter- 
ing larva 
pupated. 

Moth 
emerged. 

Length 

of  pupal 

stage. 

Individual  No. 

Winter- 
ing larva 
pupated. 

Moth 
emerged. 

Length 

of  pupal 

stage. 

Apr.     1 
Apr.    2 

...do 

...do 

Apr.    4 
Apr.    5 
Apr.     6 

...do 

Apr.     7 
Apr.     8 

...do 

do 

May     1 

Apr.  28 
Apr.  30 
May     3 
May     1 
May     2 
May     3 
May     4 

...do 

...do 

May     5 

Days,     , 
30 
26 
28 
31 
27 
27 
27 
28 
27 
26 
27 
27 
26 
25 
25 
25 
24 
24 
24 
27 
27 
28 
29 
27 
28 
28 
26 
26 
27 
27 
27 
27 
27 
27 
27 
26 
26 
26 
26 
26 
27 
27 

43 

Apr.  14 

...do 

...do 

Apr.  15 

...do 

...do 

...do 

...do 

...do 

...do 

Apr.  16 
...do 

May  11 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

May  12 
May  11 

...do 

Days. 
27 

2     

44 

45 

46        

27 

3 

4 

5        

27 
26 

47 

48 

49 

50 

51 

52 

53     

26 

6    

26 

7     

26 

8 

9     

26 
26 

10    

27 

11 

25 

54 

25 

13     

Apr.     9  l...do 

Apr.  10   ...do 

55 

56 

57. 

...do 

...do 

...do 

...do 

May  12 
...do 

25 

14     

26 

15 

do 

...do 

...do 

26 

16     

...do 

58 

59 

60 

...do 

...do 

...do 

...do 

...do 

...do 

26 

17       

Apr.  11 

...do 

do 

26 

18 

26 

19 

20 

...do 

do 

...do 

May     8 
...do 

61  

Apr.  17 
...do 

May  11 
May  12 
May  13 
...do 

24 

62 

25 

do 

63 

...do 

26 

22 

do    ... 

May     9 
May   10 
May     9 
May   10 
.do 

64 

...do 

26 

do 

65 

...do 

...do 

26 

24                    

Apr.  12 
do  

66 

67 

...do 

Apr.  18 
...do 

May   14 
May  12 
...do 

27 

25 

24 

26 

do  .... 

68 

24 

do 

May     9 
do 

69 

70 

...do 

...do 

May  13 
May   14 
...do 

25 

28 

26 

do 

May  10 
.do 

71 

...do 

26 

30                   

.do 

72 

...do 

May  15 

...do 

...do 

27 

...do 

do 

...do 

do  .... 

73 

Apr.  19 
...do 

26 

32 

74 

26 

do  .... 

.do 

75 

76 

..do 

Apr.  20 
...do 

May  16 
May  15 
May  16 

...do 

May  15 
May  16 

...do 

...do 

27 

34 

...do 

...do 

.do 

25 

77 

26 

36 

j  Apr.  14 

L..do 

do 

...do 

...do 

do  .... 

78 

79 

...do 

Apr.  21 
...do 

26 
24 

38 

80 

25 

...do 

...do 

do  .. 

81 

Apr.  22 
...do 

24 

40 

82 

24 

41 

...do 

...do 

May  11 
...do 

83 

Apr.  23     May   17 

24 

42... 

Table  II. — Length  of  pupal  periods  in  spring  brood  of  pupae— from  wintering  larvae 

collected  April  21 . 


Individual  No. 

Winter- 
ing larva 
pupated. 

Moth 
emerged. 

Length 

of  pupal 

stage. 

Individual  No. 

Winter- 
ing larva 
pupated. 

Moth 
emerged. 

Length 

of  pupal 

stage. 

1 

Anr.  22 
...do 

May   16 
May  17 
May   19 
May  18 

...do 

.do 

Days. 
24 
25 
26 
24 
23 
23 
23 
23 
23 
23 
22 
21 
20 
19 
19 
19 
20 
17 
18 
18 
18 
18 
18 
19 

25 

May    3 
May     4 
...do 

May  25 
May  22 

...do 

...do 

...do 

Days. 
22 

2 

26 

18 

3 

Apr.  23 

Apr.  24 

Apr.  25 

do 

27 

18 

4 

28 

May     5 

...do 

...do 

17 

5 

29 

30           

17 

6 

...do 

l7 

7 

...do 

...do 

31 

...do 

...do 

17 

8 

do 

.do 

32     

...do 

...do 

17 

9 

Apr.  26 
...do 

May  19 
...do 

33 

34 

...do 

...do 

...do 

...do 

17 

10 

17 

11 

Apr.  27 
Apr.  28 
Apr.  30 
May     1 
do 

...do 

...do 

May  20 

...do 

do 

35 

36 

37 

...do 

...do 

May    6 
...do 

May  23 

...do 

May  22 
May  23 

...do 

...do 

18 

12 

18 

13 

16 

14 

38 

17 

15 

39 

May     8 
...do 

15 

16.   . 

do 

do 

40  .. 

15 

17 

18 

...do 

May    3 
.  .do 

May  21 

May  20 

May  21 

.do 

41 

42 

.  .do 

May  10 

May  11 

May  12 

do 

...do 

...do 

May  25 

...do 

May  27 
May  26 
June    8 
June    6 

15 
13 

19... 

43  '.. 

14 

20     

.  .do 

44  .. 

13 

21     

.do 

.do... 

45  .. 

15 

22  

.do 

.do  .. 

46  .. 

May  13 
May   19 
May  20 

13 

23 

...do 

...do 

...do 

May  22 

1  47 

20 

24 

48... 

17 

1 

4  DECIDUOUS   FRUIT   INSECTS  AND   INSECTICIDES. 

Table  III. — Spring  brood  of pupae — summary  of  pupal  periods  shown  in  Tables  Iandll. 


Wintering  larvae  collected. 


Number 
of  indi- 
viduals. 


Maximum 
pupal  life. 


Minimum 
pupal  life. 


Average 
pupal  life. 


March  31. 

April  21.. 
Both  lots 


83 
48 
131 


Days. 


Days. 


Days. 
26.2 
18.5 
23.5 


SPRING    BROOD   OF   MOTHS. 

Duration  of  emergence. — Emergence  began  out  of  doors  March  31, 
on  which  date  we  captured  a  moth  while  collecting  wintering  mate- 
rial at  the  outdoor  apple  bin.  As  no  empty  pupal  cases  were  found 
this  may  be  considered  the  beginning  of  emergence.  Ben  Davis 
apple  trees  were  in  full  bloom  at  this  time.  From  wintering  material 
collected  March  31,  moths  began  emerging  April  9.  Some  probably 
would  have  issued  earlier  had  not  a  large  proportion  of  the  pupae  been 
injured  in  collecting.  On  again  examining  the  apple  bin,  on  April  21, 
the  numerous  empty  pupal  cases  indicated  that  about  25  percent  of 
the  moths  had  issued,  there  being  found  64  empty  cases  and  193 
larva*  and  pupae.  By  May  27  all  moths  had  emerged  from  collected 
wintering  material  except  two  belated  individuals  which  issued 
June  6  and  8.  The  latter  date  coincides  with  the  issuance  of  the  first 
moth  of  the  first  brood.  Briefly,  the  spring  brood  of  moths  issued 
during  a  period  of  2  months,  beginning  with  the  date  of  full-bloom 
of  apple  trees  (March  31). 

The  emergence  of  moths  from  collected  wintering  material  is  shown 
in  Table  IV. 

Table  IV. — Emergence  of  spring  brood  of  moths — summary  of  emergence  records  from 
wintering  material  collected  March  24,   March  31,  and  April  21. 


Number 

Number 

Number 

Number 

Number 

Date. 

of  moths 

Date. 

of  moths 

Date. 

of  moths 

Date. 

of  moths 

Date. 

of  moths 

emerging. 

emerging. 

emerging. 

emerging. 

emerging . 

Apr.  9... 

! 

Apr.  20.. 

1 

May  1... 

3 

May  12.. 

16 

May  23.. 

8 

Apr.  10.. 

2 

Apr.  21.. 

3 

May  2... 

9 

May  13.. 

12 

May  24.. 

1 

Apr.  11.. 

0 

Apr.  22.. 

4 

May  3... 

10 

May  14.. 

0 

May  25.. 

3 

Apr.  12.. 

0 

Apr.  23.. 

11 

May  4... 

13 

May  15.. 

11 

May  26.. 

2 

Apr.  13.. 

1 

Apr.24.. 

2 

May  5... 

22 

May  16.. 

11 

May  27.. 

1 

Apr.  11.. 

0 

Apr  2.1.. 

4 

May  6... 

o 

May  17.. 

8 

June  6... 

1 

Apr.  1.1 .  . 

2 

Apr.  26.. 

0 

May  7... 

0 

May  18.. 

7 

June  8... 

1 

Apr.  1H.. 

1 

Apr.  27.. 

0 

May  8... 

3 

May  19.. 

5 

Apr.  17.. 

2 

Apr.  28.. 

1 

May  9... 

0 

May  20. . 

10 

Apr.  18.. 

4 

Apr.  29.. 

2 

May  10.. 

27 

May  21.. 

6 

Apr.  19.. 

1 

Apr.  30.. 

1 

May  11.. 

" 

May  22. . 

11 

The  data  given  in  Table  IV  are  shown  graphically  in  the  accompany- 
ing curve,  figure  l. 

The  above  record  is  from  320  larva?  and  232  pupae  collected  March 
2  1.  March  31,  and  April  21   from  the  outdoor  apple  bin.     These  552 


THE   CODLING   MOTH   IN   THE   OZARKS.  D 

larvae  and  pupa3  produced  275  adults.  A  much  larger  number  of  pupae 
than  of  larvae  were  injured  in  collecting  and  failed  to  give  out  moths. 
This,  together  with  the  fact  that  193  of  the  total  number  collected 
were  taken  after  emergence  had  begun,  would  throw  the  maximum 
of  emergence  here  shown  considerably  later  than  it  should  be.  As 
before  stated,  about  25  per  cent  of  the  moths  had  emerged  in  the 
field,  from  cocoons  above  ground,  by  April  21. 

In  1907  Mr.  Dudley  Moult  on  records  the  finding  of  a  few  empty 
pupal  skins  while  collecting  wintering  material  in  an  open  packing 
shed  April  27.  This  was  25  days  after  the  apple  blossoms  had  fallen, 
a  period  of  cold  weather  occupying  the  interval.  From  material 
then  collected  moths  continued  to  issue  in  the  laboratory  until  June  1. 


Fig.  1. — Curve  showing  emergence  of  spring  brood  of  adults  of  codling  moth  (Carpocapsa  pomonella) 
from  collected  wintering  material. 


Life  of  the  moth. — Records  of  28  spring-brood  moths  emerging 
April  13-23,  and  confined  in  a  Riley  rearing  cage  out  of  doors,  show 
an  average  life  of  10.5  days.  Another  lot  of  35  moths  that  emerged 
April  25  to  May  4  gives  an  average  life  of  9.1  days.  The  life  of  the 
moths  is  largely  dependent  on  temperature.  The}'  are  able  to  lay 
fertile  eggs  in  3  to  5  days  after  emergence,  but  during  cold  weather  in 
spring  or  fall  they  remain  torpid  for  long  periods.  Moths  can  be  fed 
by  putting  into  the  cage  a  piece  of  raw  cotton  soaked  in  sirup  or 
fruit  juice.  However,  even  without  food,  if  a  sufiicient  number  of 
moths  are  confined  together,  eggs  will  be  laid  abundantly.  Data  on 
caged  spring-brood  moths  are  given  in  Tables  V  and  VI.  These 
moths  issued  from  the  wintering  material  collected  March  24  and 
March  31. 


DECIDUOUS   FRUIT   INSECTS  AND   INSECTICIDES. 
TABLH  Y.     Lift  of  spring  brood  of  moths — Cage  I. 


Moths  emerged  and  put  into 

Moths  died. 

Average 
life  of 
moths. 

Eggs  laid  (at  night). 

Date. 

Number. 

Date. 

Number. 

Date.            1  Number. 

April  13 

1 

April  19 

1 
1 
1 
4 
2 
3 
5 
1 
1 
2 
3 
1 
2 
1 
2 

10.5  days. 

April  19 

23 

April  15. . . 

•_' 

April  20 

April  24 

46 

April  16... 

1 
2 

4 
1 
1 
3 
15 

April  22 

May  2 

16 

April  17... 

April  24 

April  18... 

April  28 

April  19... 

April  29 

April  20... 

April  30 

April  J'      . 

May  1 

April  23.... 

May  2 

May  3 

Total 

30 

May  4 

May  5 

May  9 

May  10 

Escaped 

Table  VI. — Life  of  spring  brood  of  moths — Cage  II. 


Moths  emerged  and  put  into 
cage. 

Moths  died. 

Average 
life  of 
moths. 

Eggs  laid  (at  night). 

Date. 

Number. 

Date. 

Number. 

Date. 

Number. 

April  25 

4 

1 
2 
2 
9 
12 
10 

May  2 

2 
1 
1 
3 
1 
2 
5 
4 
3 
2 

9.1  days. 

May  4 

5 

April  28 

May  4 

May  8 

16 

April  29 

May  5 

May  11 

45 

Mavl 

May  6 

Mav2 

May7 

Mav3 

May  9 

May  4 

May  10 

May  11 

Total 

40 

May  12 

May  13 

May  14 

May  15 

i 

May  16 

2 
2 
5 

May  17 

Escaped 

TIIE    FIRST    GENERATION. 


FIRST-BROOD    EGGS. 


Period  of  opposition. — Eggs  were  Dot  laid  in  the  rearing  cages  as 
early  as  in  the  field,  because  of  the  lack  of  a  sufficient  number  of  the 
earliest  moths.  Eggs  collected  in  the  field  began  to  hatch  April  27, 
which,  from  the  earliest  observed  periods  of  incubation,  would  indicate 
that  oviposition  had  commenced  as  early  as  April  7.  Apple  blossoms 
had  nearly  all  fallen  by  April  7.  Eggs  were  abundant  in  the  orchard 
on  April  27,  67  eggs  being  collected  from  the  lower  branches  of  2  trees 
in  the  space  of  half  an  hour.  Of  these,  6  were  empty  shells,  2  showed 
the  black  head  of  the  larva  and  hatched  the  same  day,  36  showed  the 
red  ring,  and  23  were  undeveloped.  Eggs  continued  abundant  in 
the  orchard  during  the  early  part  of  May. 


THE   CODLING   MOTH   IX   THE   OZAEKS.  7 

The  last  unhatched  eggs  of  the  first  brood  were  found  May  27. 
Empty  shells  were  numerous  in  the  orchard  at  that  time,  but  only  3 
unhatched  eggs  were  found,  all  of  them  in  the  "black-spot"  stage. 
This  date  seems  to  be  near  the  end  of  the  first  brood  of  eggs,  and 
agrees  with  the  issuing  records  of  moths  from  collected  wintering 
material,  practically  all  moths  having  emerged  by  this  time. 

In  1907  the  last  of  the  first-brood  eggs  were  obtained  June  2, 
having  been  laid  in  a  cage  by  the  last  moths  to  emerge  from  collected 
wintering  material  kept  in  the  laboratory. 

Place  of  ovi position. — Of  67  eggs  collected  in  the  orchard  April  27, 
53  occurred  on  the  upper  side  of  leaves.  13  on  the  back  of  leaves,  and 
1  on  a  twig.  While  bagging  fruit  on  May  6  a  careful  examination 
for  eggs  was  made  on  all  the  leaves,  twigs,  and  fruit  to  be  inclosed  in 
the  bags.  There  were  78  eggs  or  empty  shells  found,  of  which  76 
were  on  the  upper  surface  of  leaves.  1  on  a  twig,  and  1  on  the  side 
of  the  fruit.  Since  but  few  apples  became  wormy  after  being  bagged, 
this  represents  nearly  the  whole  number  of  eggs  present  on  the  parts 
examined.  Some  of  the  eggs  were  at  a  considerable  distance  from 
any  fruit,  but  as  a  rule  the  moths  seemed  to  have  selected  the  fruit 
clusters,  possibly  only  because  the  foliage  there  was  denser  than  on 
isolated  shoots. 

In  the  cages  eggs  were  placed  indiscriminately  on  all  parts  of  twigs, 
leaves,  fruit,  framework  of  cage,  and  on  the  glass  panes,  always. 
however,  on  the  side  of  the  cage  from  which  most  light  came.  Twigs 
placed  in  the  middle  or  on  the  darker  side  of  the  cage  were  disregarded, 
the  moths  depositing  their  eggs  on  the  side  or  bottom  of  the  cage 
while  struggling  to  fly  out  toward  the  light. 

Fertility. — Practically  all  eggs  observed  were  fertile,  whether  laid 
in  cages  or  collected  in  the  orchard.  Often  a  few  sterile  eggs  were 
deposited  in  the  cages  before  oviposition  proper  began.  When  eggs 
were  laid  in  considerable  numbers  they  were  all  fertile. 

Length  of  incubation  period. — The  egg  stage  was  greatly  lengthened 
by  periods  of  cool  weather  such  as  are  apt  to  occur  in  early  spring. 
The  first  eggs  obtained  in  cages  were  deposited  the  night  of  April  19. 
These  were  subjected  to  very  cool  weather,  including  frost,  and  gave 
a  maximum  period  of  21  days,  or  an  average  of  19.6  days.  Eggs 
deposited  the  night  of  April  24  experienced  part  of  the  same  spell  of 
cool  weather,  including  frost,  and  required  an  average  of  17  days  to 
hatch.  With  the  advent  of  warm  weather  the  egg  stage  was  rapidly 
shortened.  Eggs  deposited  May  8  hatched  in  8^  days,  and  the  lot 
laid  Mav  10  hatched  in  7h  davs.  Undoubtedlv  the  last  eggs  of  the 
first  brood  would  show  the  uniform  period  of  5  days  required  for 
second-brood  and  third-brood  eggs  laid  during  June.  July,  and  August. 
In  Table  YTI  are  shown  the  incubation  records  of  first-brood  e^iis 

cc 

deposited  in  outdoor  cages. 
30490°— Bull.  80—12 2 


8  DECIDUOUS    FRUIT    INSECTS   AND    INSECTICIDES 

Table  VII. — First-brood  eggs — incubation  records  of  eggs  laidin  Cages  land  II  (recorded 

in  Tables  V and  VI). 

A.  21  EGGS  LAID  IN  CAGE  I. 


Number 

of  eggs. 

Whan 

laid 

(night). 

Red  ring 
apj)eared. 

Black- 
spot 
appeared. 

When 
hatched. 

length  of 
egg  stage. 

5 
11 
3 

Apr.   19 

...do 

...do 

...do 

Apr.  27 

...do 

...do 

..do 

May     4 
May     5 

...do 

...do 

Mav     6 
Mav     8 
May     9 
May   10 

Days. 
17 
19 
20 
21 

B.  4G  EGGS  LAID  IN  CAGE  I. 


j 

Apr.   21 

Mav     2 

May   10 

May   11 

10 

2 

...do 

..do 

May     9 

Mav    12 

17 

6 

...do 

...do 

May   10 

...do 

17 

30 

...do 

...do 

May  11 

...do 

17 

4 

...do 

May     3 

...do 

...do 

17 

1 

...do 

Mav     2 

...do 

May   13 

18 

1 

...do 

May     3 

Mav    14 

19 

('.  Ki  EGGS  L\ID  IN  CAGE  II. 


Mav     8 


/May   17 
\    a.  m. 


}  *.. 


D.  45  EGGS  LAID  IN  CAGE  II. 


45 

May    10 

(May    17 
1     p.  m. 

h 

|  May   18 

1     a.  m. 

FIRST-BROOD  LARV.E. 


Period  of  hatching. — The  date  of  the  earliest  hatching  of  larvae 
can  be  put  fairly  accurately  at  about  April  27  (3  weeks  after  petals 
had  fallen),  as  on  that  day  out  of  67  eggs  collected  in  the  orchard 
only  6  were  empty  shells  and  2  in  the  black-spot  stage,  hatching 
the  same  day.  No  wormy  apples  were  found  until  May  4,  the  calyx 
lobes  probably  concealing  their  work  for  several  days.  Larvae  con- 
tinued  to  enter  the  fruit  in  numbers  during  nearly  the  whole  of  May. 
The  last  of  the  brood  probably  entered  during  the  first  week  of  June, 
which  is  allowing  10  days  from  the  time  of  the  last  observed  unhatched 
egg  in  the  orchard.  The  great  majority  of  the  first  brood  of  larvae 
entered  the  fruit  during  May. 

Thus  it  will  be  seen  that  up  to  this  time  the  different  stages  of 
the  insect,  instead  of  showing  an  increasing  tendency  to  occupy  a 
longer  time,  have  actually  become  more  compact.  While  it  required 
about  2\  months  for  the  wintering  larva*  \o  pupate,  the  spring  moths 
issued  within  a  space  of  '2  months  and  the  first  brood  of  larva1  hatched 
in  scarcely  more  than  ir>  days.  This  is  readily  explainable  from  the 
influence  of  temperature  on  the  different  stages.     The  earliest  spring 


THE   CODLING   MOTH   IN   THE   OZARKS.  9 

pupal  stages  lasted  a  month,  but  the  later  individuals  to  transform 
spent  only  2  weeks  as  pupae;  so  that  the  time  of  emergence  of  the 
spring  moths  was  shortened  by  15  days.  Again,  the  first  eggs 
required  20  days  to  hatch,  and  the  last  only  5,  a  shortening  by  another 
15  days  of  the  period  during  which  the  first  brood  of  larva?  entered 
the  fruit. 

In  1907  the  first  larva  was  found  in  the  orchard  May  18,  newly 
hatched,  and  in  the  act  of  entering  the  calyx.  This  was  6  weeks 
after  the  petals  had  fallen  from  the  apple  trees.  Several  wormy 
apples  were  found  May  23,  and  they  soon  became  abundant.  On 
June  17  to  20,  observations  by  Mr.  Dudley  Moulton  at  Bentonville, 
Ark.,  and  by  the  writer  at  Siloam  Springs  indicated  that  the  first 
brood  had  nearly  all  entered.  Over  500  wormy  apples  were  collected 
in  orchards  at  the  two  places,  but  no  larvae  just  entering  were  found, 
the  smallest  larvae  having  burrowed  to  the  core. 

Maturing  of  larvse. — In  1908  the  first  cocoon  was  found  under  a 
band  May  27,  and  contained  a  newly  transformed  pupa  (soft  and 
white),  indicating  that  the  larva  had  left  the  fruit  not  later  than  May 
24.  Two  full-grown  larvae  left  picked  fruit  May  26,  the  fruit  having 
been  collected  in  the  orchard  that  day.  The  band  record  from  18 
trees  (page  24)  indicates  that  the  last  of  the  first  brood  of  larvae 
went  into  cocoons  about  July  15,  or  52  days  after  the  first  larva  left 
the  fruit.  This  gives  an  increase  of  about  a  week  over  the  time  be- 
tween the  first  and  last  entering  larvae  of  this  brood. 

In  1907  the  first  mature  larvae  left  picked  fruit  June  12.  On  June 
17  many  larvae  and  some  pupae  were  taken  from  bands,  the  last  pre- 
vious examination  of  the  bands  being  on  June  10.  In  1906  larvae 
had  begun  to  spin  cocoons  by  June  5,  as  indicated  by  a  sending  of 
wormy  fruit  from  Bentonville,  Ark.,  by  Mr.  W.  M.  Scott  to  Mr.  Moul- 
ton.    Several  larvae  had  spun  up  en  route. 

Period  in  fruit. — Several  of  the  earlier  larvae  of  the  first  brood 
hatched  and  were  placed  on  bagged  fruit  May  4.  Six  larvae  reached 
maturity,  leaving  the  fruit  May  26-29,  after  an  average  life  in  the 
apple  of  23.8  days,  the  minimum  being  22  and  the  maximum  25  days. 
A  greater  range  would  probably  occur  in  the  field  between  larvae 
in  exposed  fruit  and  those  in  the  shaded  interior  of  the  trees. 

Larval  life  in  cocoon. — Forty-three  larvae  which  became  full  grown 
before  July  10  showed  an  average  interval  of  7.2  days  between  leav- 
ing the  fruit  and  pupation  when  kept  in  vials  out  of  doors.  The 
shortest  interval  was  3  days  and  the  longest  19.  The  normal  time 
in  the  orchard  is  probably  nearer  the  minimum  here  shown,  as  in 
the  glass  vials  many  larvae  seemed  to  spend  an  unusually  long  time 
trying  to  build  a  suitable  cocoon.  Individual  records  on  this  stage 
are  given  in  Table  VIII. 


10 


DECIDIOLS    PBUIT    INSECTS   AND    INSECTICIDES. 


KIRST-BROOD    PI   II 

First-brood  larvae  began  to  pupate  May  27,  just  a  week  after  the 
last  Btragglers  of  the  wintering  larvae  under  observation  had  pupated. 
Thus  Gist-brood  pupae  appeared  before  the  last  of  the  spring  brood 
had  given  out  moths,  the  extent  of  the  overlap  being  12  days. 

Of  42  first-brood  pups  observed,  the  average  duration  of  the  stage 
was  10.7  davs,  ranging  from  9  to  13  days.  The  total  period  from 
the  time  the  larva  left  the  fruit  until  the  adult  issued  averaged  17.8 
days,  with  a  range  of  from  13  to  21  days.  As  before  suggested,  larvae 
not  confined  in  vials  would  probably  pupate  sooner,  thus  shortening 
the  " cocoon  stage."  Individual  records  of  first-brood  pupae  are 
shown  in  Table  VIII. 

Table   VIII.     Pupal  periods  and  cocoon  stages  of  first  generation. 


Individual  No. 


Larva 
left 
fruit. 


1 May  29 


4 May   30 

5 do 

ti do 


7 May   31 

8 June    2 

0 do 


10 do 

11 June    3 

13 June    4 

13 June    5 

14 do.... 


US do 

June    6 

17 do 

June    8 

...do 

June  9 
June  11 
June  15 
June  16 
June  21 
June  23 
...do.... 


18 

19 

20 

21 

22 

23 

24 





27 j  June  24 

28 ...do.... 


June  27 

June  28 
June  30 
July  1 
July  2 
..do 


...do.... 
July     3 

July     7 
...do.... 


Julv 
July 

...do. 

...do. 


Larva 
pupated. 


June  2 

..do 

..do 

June  3 

..do 

June  5 
June  4 
June  5 
June  6 
June  7 
June  6 
June  Q 
June  8 
June  12 
June  21 
June  11 
June  13 

..do 

June  16 
..do..... 

..do 

June  19 
June  23 
June  24 
June  29 


Moth 
emerged. 


July 

July 

July 

July 

July 

July 

July 

July 

July   u 

July  16 

Julv     B 

July  n 

Julv  26 
Julv  23 
Julv    I.") 

July   18 

Julv    'J.". 


June  12 

..do 

..do 

..do 

June  13 
June  18 
June  15 
June  16 
..do.... 
June  18 
June  16 
June  21 
June  19 
June  23 
July  3 
June  22 
Juno  24 

..do 

June  26 
June  28 
June  25 
June  30 
July     5 

..do 

Julv  11 
July  17 
July  12 
Julv  16 
Julv  17 
July  13 
July  17 
..do.... 
Julv  18 
Julv  20 
Julv  -27 
Julv  is 
Aur.  1 
Aug.  7 
Aug.  2 
Julv  26 
Julv  29 
Aug.    4 


Length  I     Total 

of  pupal  !  time  in 

stage.       cocoon. 


Days. 


10 
10 
10 

9 

10 
13 
11 
11 
10 
11 
10 
12 
11 
11 
13 
11 
11 
11 
10 
12 
8 
11 
12 
11 
12 
10 

10 

11 

10 
10 
10 
12 
10 

0 

11 
B 

12 
12 
10 

n 

10 


Days. 


l  [RST-BROOD    IfOTB  - 


The  earliest  first-brood  moth  emerged  June  8,  on  which  (Into  the 
last  belated  moth  of  the  spring  brood  also  issued.  Sixteen  of  the 
earliest  moths,  caged  June  8  L5,  showed  an  average  life  of  6.2  days. 
OvipositioE  began  5  days  after  the  first  moth  was  caged.     In  1907, 


THE   CODLTXG   MOTH   TX   THE   OZARKS. 


11 


when  a  large  number  of  moths  were  caged  on  the  same  date,  eggs  were 
obtained  on  the  third  day.  A  record  of  first-brood  moths  confined  in 
a  cage  is  given  in  Table  IX. 

Table  IX. — Life  of  first-brood  moths  {Cage  III),  reared  from  first-brood  larvae  from 
earliest  wormy  apples  collected  in  orchard,  and  from  earliest  larvae  reared  in  bagged 
fruit. 


Moths  emerged  and  put 
into  cage. 

Moths  died 

. 

Average 
life  of 
moths. 

Eggs  laid  (at  night). 

Date.               Number. 

Date. 

Number. ' 

Date. 

Number. 

June   8 1 

June  16 

5 

•6.2  days. 

June  13 

2 

June  9 1 

June  IS. ... 

June  14 

16 

June  11...                                1 

June  19  . 

26 

18 

104 

25 

June  12 5 

June  21 

June  16 

Junel4 2 

Escaped 

June  17 

June  15                                  11 

Total 

June  IK 

16  | 

Total 

Total 21 

191 

In  1907  no  first-brood  moths  were  obtained  until  June  25.  In  1906 
Mr.  Moult  on  records  the  issuing  of  a  moth  on  June  19  from  apples 
sent  from  Bentonville,  Ark. 

LENGTH    OF   LIFE    CYCLE    OF  FIRST   GENERATION. 

The  interval  between  the  emergence  of  the  first  adult  of  the  win- 
tering brood  and  the  earliest  first -brood  moth  was  69  days.  Starting 
with  a  spring  moth  emerging  after  the  weather  became  warm,  the 
fife  cycle  would  be  much  shorter.  A  moth  emerging  May  5  might 
lay  eggs  May  10.  Eggs  laid  on  the  latter  date  required  7 J  days  to 
hatch.  This,  together  with  24  days  in  the  fruit  and  18  days  in  the 
cocoon,  gives  a  total  of  about  54  days  as  an  average  time  for  the  latter 
half  of  the  first  generation. 

THE    SECOND    GENERATION. 


SECOND-BROOD    EGGS. 


The  earliest  of  the  first  brood  of  moths  began  depositing  eggs  on 
the  night  of  June  13.  In  1907  second-brood  eggs  were  not  laid  in  cages 
until  July  5.  All  eggs  of  this  brood  required  a  nearly  uniform  period 
of  5  days  for  incubation.  In  Table  X  is  given  a  record  of  the  incuba- 
tion of  some  of  the  earlier  eggs  of  this  brood. 

Table  X. — Second-brood  eggs — incubation  periods  of  eggs  laid  in  Cage  III  (recorded  in 

Table  IX). 


Number   EgfJaid   Red  ring      Black 

ofesres  (at  ap"         spot  ap 

66      I  night),      peared.      peared 


Whp,,       Length 

hashed.      °tfe^ 
!    stage. 


26 

18 

104 

25 


June  15     June  18     June  20     June  21 

June  16     June  19     June  21    ..ado 

June  17    ...do June  22   ajune  22 

June  18  ,  June  20   1  June  23 


Days. 

H 

5 
5 

H 


«  At  night. 


12 


DECIDUOUS   FRUIT    TNSKCTS   AND   INSECTICIDES. 


NKCOXD-BROOD    LARV.K. 

Period  of  hatching. — According  to  records  of  oviposition,  the  first 
larvae  of  the  second  brood  would  have  hatched  June  18.  They  began 
ha  telling  in  numbers  in  the  cages  June  21.  Reared  larvae  entering 
fruit  as  late  as  August  3  were  undoubtedly  of  the  second  brood,  as 
they  pupated  on  reaching  full  growth.  Some  of  the  brood  probably 
hatched  later  still,  making  a  total  period  of  entrance  to  the  fruit  of 
perhaps  55  days  for  such  larvae  of  this  brood  as  pupated. 

Maturing  oflarvse. — The  band  record  (p.  24)  indicates  that  second- 
brood  larvae  began  to  leave  the  fruit  by  July  15.  The  first  of  the 
reared  larvae  left  July  13,  and  were  from  eggs  laid  4  days  later  than 
the  earliest,  so  mature  second-brood  larvae  may  have  appeared  by 
July  10.  The  band  records  of  both  1907  (p.  23)  and  1908  (p.  24) 
indicate  that  the  last  of  the  second  brood  left  the  fruit  early  in  Sep- 
tember. 

Period  in  fruit. — A  large  number  of  second-brood  larvae  hatching 
during  the  night  of  June  22  were  transferred  to  bagged  fruit  June  25. 
Seventeen  of  these  reached  maturity  after  an  average  time  in  the  fruit 
of  24.6  days,  the  time  ranging  from  21  to  31  days.  The  individual 
records  are  given  in  Table  XI. 

Table  XI. — Life  of  second-brood  larvae,  reared  in  bagged  fruit  on  trees  (eggs  recorded  in 

Table  X). 


Number 

When 

Date  of 
leaving 
fruit. 

Time  in 

oflarvse. 

hatched. 

fruit. 

Night. 

Days. 

1 

June  22 

July  13 

21 

4 

...do 

July   14 

22 

1 

...do 

July   15 

23 

4 

...do 

July   16 

24 

1 

...do 

July   17 

25 

2 

...do 

July   18 

26 

2 

...do 

July   19 

27 

1 

...do 

July  20 

28 

1 

...do 

Julv   23 

31 

Several  of  the  same  lot  of  larvae  were  put  on  picked  fruit  and  kept 
in  jars  out  of  doors.  Most  of  these  spun  cocoons  in  the  fruit,  and  had 
pupated  before  the  fact  was  noticed.  Three  of  them,  however,  left 
the  fruit  after  periods  of  21  and  22  days.  The  fact  that  these  larvae 
had  been  kept  in  jars  instead  of  on  bagged  fruit  seems  to  have 
hastened  development,  as  the  average  time  from  oviposition  to  emer- 
gence of  adult  of  11  individuals  of  this  lot  was  42.3  days,  as  against 
49.5  days  for  the  17  individuals  on  bagged  fruit.  Nine  second-brood 
larva'  hatching  July  28  to  August  3  were  reared  in  picked  fruit  in  jars, 
and  reached  maturity  in  from  16  to  20  days,  the  average  being  17.7 
days.     Individual  records  of  this  lot  are  given  in  Table  XII. 


THE   CODLING  MOTH   IN   THE   OZARKS.  13 

Table  XII. — Life  of  second-brood  larvx,  reared  in  picked  fruit  in  jars  out  of  doors. 


Number 

When 

Date  of 

leaving 

fruit. 

Time  in 

of  larvae. 

hatched. 

fruit. 

Days. 

2 

July  28 

Aug.  15 

...do 

Aug.  14 

17 

July  31 

Aug.  17 

17 

Aug.    2 

Aug.  20 

18 

Aug.    3 

Aug.  22 

19 

...do 

Aug.  23 

20 

...do 

Aug.  19 

16 

...do 

...do 

16 

In  1907  the  period  in  the  fruit  was  determined  for  33  second-brood 
larvae  which  hatched  July  10-15.  All  were  reared  in  picked  fruit 
kept  in  the  laboratory.  The  shortest  time  was  15  days,  longest  22, 
average  18.1  days.  The  1907  rearings  are  tabulated  in  Table  XIII. 
Table  XIII. — Life  of  second-brood  of  larvae,  reared  in  picked  fruit,  in  laboratory — 1907 


Number 

Date  of 

Date  of 
leaving 
fruit. 

Time  in 

of  larvae. 

hatching. 

fruit. 

Days. 

2 

July  10 

July  27 

17 

2 

...do 

July  29 

19 

1 

...do 

July  30 

20 

1 

July  15 

...do 

15 

2 

...do 

July  31 

16 

9 

...do 

Aug.    1 

17 

7 

...do 

Aug.    2 

18 

4 

...do 

Aug.     3 

19 

1 

...do 

Aug.    4 

20 

2 

...do 

Aug.    5 

21 

2 

...do 

Aug.     6 

22 

Larval  life  in  cocoon. — Of  75  larvae  maturing  from  July  12  to  Sep- 
tember 1,  the  time  between  leaving  the  fruit  and  pupation  (in  vials 
out  of  doors)  varied  from  3  to  21  days,  with  an  average  of  11.86  days. 
The  remarks  on  this  stage  of  the  first-brood  larvae  would  also  apply 
here.     Individual  records  are  shown  in  Table  XIV. 


SECOND-BROOD  PUP^E. 


Pupae  appeared  out  of  doors  as  late  as  September  14.  These,  how- 
ever, were  from  larvae  that  left  the  fruit  September  1  or  before,  and 
only  a  few  larvae  leaving  the  fruit  later  than  August  20  transformed. 
In  the  laboratory  pupae  appeared  well  into  November.  In  1907  larvae 
appearing  under  bands  later  than  August  26  generally  failed  to  pupate, 
so  that  the  last  pupae  in  both  seasons  appeared  early  in  September. 

Of  78  second-brood  pupae,  from  larvae  maturing  after  July  12  and 
until  September  1,  the  longest  pupal  stage  was  17  days,  shortest  8, 
average  10.5  days.  The  longest  total  period  in  cocoon  was  38  days, 
shortest  12,  average  20.4  days.  This  material  was  kept  in  small 
vials,  and  the  period  between  leaving  the  fruit  and  pupation  was 
probably  abnormally  long,  on  account  of  the  difficulty  in  spinning  a 
suitable  cocoon.     The  individual  records  are  given  in  Table  XIV. 


14  DECIDUOUS   FRUTT   INSECTS  AND  INSECTICIDES. 

Tabi.k  XIV.     Pupal  periods  and  cocoon  stages  of  second  generation. 


Individual  No. 


Larva 
left  fruit. 


July  12 
...do 

July  13 
...do 

July   14 

...do 

...do 

...do 

July   15 

July   16 

...do 

...do.... 
...do.... 

July   17 

July  18 
...do 

July   19 

...do 

...do.... 

July   20 

July  21 
...do 

July  23 
...do 

July  24 
...do 

July  25 

July  29 

Aug.  1 
...do 

Aug.  2 
...do 


Larva 
pupated. 


...do.... 
Aug.  3 
...do.... 
...do.... 
Aug.  4 
...do.... 
...do.... 
...do.... 
Aug.  5 
...do.... 
...do.... 
Aug.  6 
..do.... 
Aug.  7 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
Aug.  11 
...do 


...do.... 
...do.... 
Aug.  13 
Aug.  14 
Aug.  15 
..do.... 
...do.... 
Aug.  16 

...do 

...do.... 
Aug.  17 

...do 

...do 

Aug.  19 
...do... 
Aug.  20 
...do... 
Aug.  21 
Aug.  24 
Aug.  25 
Aug.  26 
Aug.  27 
Aug.  28 
Aug.  30 
Sept.  1 


July  17 
July  22 
July  21 
July  24 
July  17 
July  28 

..do 

July  31 
July  29 
July  25 

...do..... 

>  July  22 
July  28 

i  Aug.  2 
July  22 
July  26 

...do 

...do.... 
July  28 
Aug.  7 
July  28 
July  29 
July  31 
Aug.  4 
July  30 
Aug.  1 
Aug.  2 
Aug.  11 
Aug.  16 
Aug.  11 
Aug.  6 
Aug.  11 
Aug.  12 
Aug.  11 
Aug.  14 
Aug.  17 
Aug.  11 
Aug.  12 
Aug.  16 
Aug.  25 
Aug.  11 
Aug.  13 

...do 

Aug.  10 
Aug.  14 
Aug.  13 
Aug.  15 
Aug.  16 
Aug.  18 
Aug.  21 

...do 

Aug.  17 
Aug.  18 
Aug.  19 
Aug.  21 
Aug.  18 
Aug.  21 
Aug.  31 
Aug.  19 
Aug.  26 
Aug.  24 

...do 

Aug.  25 
Aug.  20 
Aug.  29 
Aug.  30 
Aug.  25 
Aug.  30 
Aug.  29 
Sept.  6 
Auk.  28 
Sept.  II 
Sept.  1 
Sept.  8 
Sept.  6 
Sept.  1 
Sept.  9 
Sept.  13 


Moth 
emerged 


July  26 
Aug.  2 
July  31 
Aug.  2 
July  27 
Aug.  6 
Aug.  7 
Aug.  10 
Aug.  7 
Aug.    3 

...do.... 
July  30 
Aug.  7 
Aug.  11 
July  31 
Aug.  4 
Aug.     3 

...do.... 
Aug.  6 
Aug.  18 
Aug.  6 
Aug.  7 
Aug.  10 
Aug.  16 
Aug.  8 
Aug.  11 

...do.... 
Aug.  19 
Aug.  27 
Aug.  19 
Aug.  16 
Aug.  19 
Aug.  22 
Aug.  19 
Aug.  25 
Aug.  28 
Aug.  22 
Aug.  21 
Aug.  27 
Sept.  5 
Aug.  20 
Aug.  21 
Aug.  22 
Aug.  18 
Aug.  23 

...do 

Aug.  25 
Aug.  27 
Aug.  28 
Aug.  30 
Sept.  1 
Aug.  27 

...do..... 
Aug.  30 
Aug.  31 
Aug.  27 
Aug.  31 
Sept.  12 
Aug.  28 
Sept.  6 
Sept.  3 
Sept.  5 
Sept.  6 
Aug.  30 
Sept.  8 
Sept.  10 
Sept.  6 
Sept.  11 
Sept.  10 
Sept.  17 

Sept.  10 

Oct.  1 
Sept.  12 
Sept.  20 
Sept.  16 
Sept.  14 
Sept.  20 
Sept.  25 


Time  as 
pupa. 


Days. 


10 


THE   CODLING   MOTH   TX   THE   OZARKS. 


15 


SECOND-BROOD   MOTHS. 

Moths  of  the  second  brood  were  obtained  from  reared  material 
July  25.  Moths  emerged  in  abundance  during  August  and  in  dimin- 
ishing numbers  throughout  September.  The  last  one  to  emerge  out 
of  doors  appeared  October  1. 

The  earliest  moths  of  this  brood  were  not  obtained  in  sufficient 
numbers  to  get  the  first  possible  third-brood  eggs.  Oviposition  in  a 
cage  began  on  August  5  by  moths  the  first  of  which  emerged  July  30. 
The  record  of  this  cage  is  given  in  Table  XV. 


Table  XV 


-Life  of  second-brood  moths  {Cage  IV),  reared  from  second-brood  larvx 
recorded  in  Table  XI. 


Moths  emerged  and  put  into  cage.               Eggs  laid  (at  night). 

Moths  died. 

Date. 

Number. 

Date. 

Number. 

Date. 

Number. 

July  30 

1 

! 

3 

I 

3 

1 

2 
2 
55 
54 

(female)    1 

Julv  31 

(female)    1 

August  2 

August  8 : . . . 

August  11 

(female)   2 

August  3 

August  9 

August  12 

(female)   2 

August  4 

do 

(male)      1 

August  6 

August  13 

(male)      1 

August  7 

Lost  or  escaped 

5 

August  11 

Total 

13 

LENGTH   OF  LIFE    CYCLE    OF   SECOND   GENERATION. 

The  interval  between  the  emergence  of  the  earliest  first-brood 
moth  (June  8)  and  the  earliest  of  the  second  brood  (July  25)  gives  a 
period  of  47  days  for  the  life  cycle.  Records  of  19  individuals,  the 
larvae  being  reared  in  bagged  fruit  on  trees,  give  an  average  of  49.5 
days  from  oviposition  to  emergence.  Adding  5  days  as  the  interval 
from  emergence  to  oviposition  gives  54.5  days  as  the  total  for  the  gen- 
eration. The  minimum  time  thus  shown  was  45  and  the  maximum 
67  days.     Records  of  these  19  individuals  are  given  in  Table  XVI. 


10 


DECIDUOUS    PBUIT    [NSECTS   AND   INSECTICIDES. 


Table  XVI. — Records,  from  oviposition  to  emergence  of  adult,  of  19  individuals  of  the 
teeond  generation  reared  from  moths  recorded  in  Table  IX — larvde  reared  in  bagged 
fruit  on  trees. 


Individual  No. 

Egg  laid 

(at 
night). 

Egg 

hatched 
(at 

night). 

Larva  left 
fruit. 

Larva 
pupated. 

Moth 
emerged. 

Time 
from 
oviposi- 
tion to 
emer- 
gence of 
adult. 

1 

June  17 

...do 

June  22 
...do 

July     13 
July     14 
...do 

July     24 
July     17 
July     28 
...do 

Aug.    2 
July   27 
Aug.     6 
Aug.     7 
Aug.  10 
Aug.     7 
Aug.     3 
...do 

Days. 
46 
40 

3 

...do 

...do 

50 

4 

...do 

...do 

...do 

51 

6 

...do 

...do 

...do 

July     15 
July     16 

...do 

July     31 
July     29 
July     25 
...do 

54 

6 

...do 

...do 

51 

7 

...do 

...do 

47 

8 

...do 

...do.... 

47 

9 

...do 

...do.... 

...do 

July     22 
July     28 
Aug.      2 
July     22 
July     26 

...do 

Aug.      7 
Aup.       4 

July   30 
Aug.     7 
Aug.  11 
July   31 
Aug.     4 
Aug.    3 
Aug.  18 
Aug.  16 
Aug.     4 
...do 

43 

10 

...do 

...do.... 

...do 

51 

11 

...do 

...do 

July      17 
July     18 
...do 

55 

12 

...do 

...do 

44 

13.... 

...do 

...do.... 

48 

14 

15 

...do 

...do 

...do 

...do.... 

July     19 
July     20 
July     23 

47 
62 

16 

...do 

...do.... 

60 

17 

...do.... 

...do.... 

Transformed  in  fruit. 
do 

48 

18 

...do 

...do.... 

48 

19.... 

...do.... 

...do.... 

....do... 

Aug.    5 

49 

Eleven  individuals  from  the  same  lot  as  the  above  were  reared  in 
picked  fruit  in  jars  out  of  doors,  and  show  an  average  of  42.3  days 
from  oviposition  to  emergence,  which  would  indicate  about  47  days 
as  the  length  of  the  life  cycle.     The  records  are  shown  in  Table  XVII. 


Table  XVII. — Records,  from  oviposition  to  emergence  of  adult,  of  11  individuals  of  the 
second  generation  reared  from  moths  recorded  in  Table  IX — larvae  reared  in  picked 
fruit,  in  jars  out  of  doors. 


Individual  No. 

Egg  laid 

(at 
night). 

Egg 
hatched 

(at 
night). 

Larva  left 
fruit. 

Larva 
pupated. 

Moth 
emerged. 

Time 
from 
oviposi- 
tion to 
emer- 
gence of 
adult. 

June  17 
...do 

June  22 
...do 

July     13 
July     14 

...do 

Transforn 

July     21 
July     17 

July     20 
ed  in  fruit. 

July   31 
July   28 
July   31 
July   26 
July   26 
July   28 
July   30 
July   31 
Julv   2i\ 
Aug.    2 
...do 

Days. 
44 

2 

41 

4                                                      ... '.'. 

...do 

...do 

...do 

...do 

44 
38 

:, 

.do... 

...do 

do 

39 

c, 

...do... 

...do 

do 

41 

7 

..do... 

...do 

do 

43 

s 

do 

...do 

do 

44 

do... 

...do 

do 

39 

1(1 

do... 

..do 

do 

46 

11 

...do.... 

do 

do 

46 

1 

In  1907  records  of  30  individuals  reared  in  picked  fruit  in  the 
laboratory  gave  a  minimum  time  from  oviposition  to  adult  of  34 
days,  maximum  68,  average  39.1   days.     Allowing  5  days  between 


THE   CODLING   MOTH   IN   THE   OZARKS. 


17 


emergence  and  oviposition,  the  length  of  the  life  cycle  would  be: 
Minimum,  39 ;  maximum,  73 ;  average,  49  days.  These  indoor  records 
show  an  average  life  cycle  5  days  shorter  than  the  outdoor  records 
(on  bagged  fruit)  of  1908.  Table  XVIII  gives  a  record  of  the  1907 
rearings. 

Table  XVIII. — Records  from  oviposition  to  emergence  of  adult  of  30  individuals  of 
the  second  generation  reared  in  1907  from  larvae  and  pupae  of  the  first  generation 
collected  from  bands — material  kept  in  laboratory. 


Individual  No. 

Egg 
laid. 

Egg 
hatched. 

Larva 
left  fruit. 

Moth 
emerged. 

Time 
from  ovi- 
position 
to  emer- 
gence of 

adult. 

1 

July     5 
...do 

July  10 
...do 

July  27 
...do 

Aug.  15 
Aug.  12 

...do 

...do 

Days. 
41 

2                                                                             

38 

3 

...do 

...do 

July  29 
...do 

38 

4 

...do 

...do 

38 

5 

6 

July   10 
...do 

July  15 
...do 

July  30 
July  31 

...do 

Aug.    1 

...do 

...do 

Aug.  15 
Aug.  13 
Aug.  14 

...do 

...do 

...do 

36 
34 

7 

8 

10!                                            .".'.'.'.'.'..'.'.'.".'.. 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

35 
35 
35 
35 

ii                                                 

...do 

...do 

...do 

...do 

35 

12 

13 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

Aug.  16 

...do 

Aug.  25 
Aug.  15 

...do 

...do 

Aug.  21 
Aug.  22 
Aug.  27 
Aug.  15 

...do 

35 
37 

14 

15 

16 

is! !!!!!!!!!."!!!."!!!!."!!!!!!!!;!!!!!;!!!!!!!!!!!!!!!! 

19 

20 

21 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

Aug.    2 

...do 

...do 

...do 

...do 

...do 

37 
46 
36 
36 
36 
42 
43 
48 

22 

...do 

...do 

Aug.    3 
...do 

36 

23 

...do 

...do 

36 

24 

...do 

...do 

...do 

Aug.  16 
...do 

37 

25 

...do 

...do 

...do 

37 

26 

...do 

...do 

.  .do 

Sept.  16 
Aug.  17 
Sept.    1 
Aug.  15 
...do 

68 

27 

...do.... 

...do 

Aug.    4 
Aug.    5 

(«) 

M 

38 

28 

...do 

...do.... 

53 

29 

...do 

.do.... 

36 

30 

...do.... 

..do 

36 

a  Spun  cocoon  in  fruit. 


THE    THIRD    GENERATION. 


THIRD-BROOD   EGGS. 


In  the  cages  third-brood  eggs  were  first  secured  August  5.  The 
calculated  time  for  their  first  appearance  in  the  field  is  10  days 
earlier.  The  last  eggs  observed  were  laid  in  a  cage  October  16  by 
moths  emerging  up  to  October  1. 

All  second-brood  and  third-brood  eggs  laid  before  August  28 
hatched  in  5  days,  the  usual  summer  incubation  period.  During 
September  the  egg  stage  was  gradually  lengthened  toward  the  maxi- 
mum period  shown  in  early  spring  eggs.  The  eggs  from  which  the 
third-brood  larvae  were  reared  incubated  as  shown  in  Table  XIX. 


IS 


i)l(  IDUOUS   FIUTTT   TNSECTS   AND   INSECTICIDES. 


Table  XIX. — Incubation  periods  of  third-brood  eggs  laid  in   Cage  IV  (recorded  in 

Table  XV). 


Number 

of  eggs. 

Eggs  laid  (at 
night). 

Red  ring 
appeared. 

Black  spot 
appeared. 

When  hatched. 

Length  of 
egg  stage. 

54 

A.og.8 

Aug.  9 

Aug.  11 

Aug.  12 

Aug.  13 

Aug.  14,  a.  m 

Days. 
5 

Aug.  14,  a.  m 

Aug.  14,  night... 

5 

Records  of  other  eggs,  mostly  of  the  third  brood,  laid  throughout 
the  latter  part  of  the  season  are  given  in  Table  XX. 

Table  XX. — Incubation  periods  of  miscellaneous  second-brood  and  third-brood  eggs. 


Number 
of  eggs. 


Eggs  laid  (at 
night). 


Red  ring 
appeared. 


Black  spot 
appeared. 


When  hatched. 


Length  of 
egg  stage. 


July  30.. 

Aug.  12. 
Aug.  13. 
Aug.  28. 
Aug.  29. 
Sept.  7.. 

Sept.  11. 
Sept.  17. 


Sept.  23.... 
Sept.  24-27. 
Oct.  16 


Aug.  14,  p.m. 


Aug.  17,  a.  m. 


Aug.  30. 
Aug.  31. 
Sept.  9.. 

Sept.  13. 


Sept.  2 

Sept.  4 

Sept.  13,  a.  m. 


Sept.  16 

Sept.  24,  a.  m. 


Oct.  18-19. 


Oct.  3.. 
OctVw! 


Aug.  4,  evening 

and  night. 
Aug.  17,  night... 
Aug.  18,  p.  m. .. 

Sept.  3,  p.  m 

Sept.  5 

Sept.  13,  p.  m. 

and  night. 

Sept.  17,  m 

Sept.  25,  p.  m. 

and  night. 

Oct.  5,  a.  m 

Oct.  9-15 

Dried  up 


Days. 
5 

5 

5 

5J-6 


to 


Hi 

14-18 
13+ 


THIRD-BROOD    LARV.E. 


In  the  cages  the  first  hatching  of  third-brood  larvae  was  on  August 
14.  Judging  from  the  emergence  of  second-brood  moths  July  25, 
third-brood  larvae  probably  appeared  in  the  field  during  the  first  wreek 
of  August.  Owing  to  the  early  dropping  of  the  small  crop  of  fruit  in 
1908,  field  observations  on  larvae  entering  fruit  could  not  be  made 
during  September.  In  the  cages  larvae  continued  to  hatch  in  numbers 
up  to  September  20,  and  the  last  on  October  15.  The  last  lot  of  eggs 
developed  as  far  as  the  black-spot  stage  on  October  29,  but  failed  to 
hatch. 

As  the  harvesting  of  the  apple  crop  in  this  region  ordinarily  begins 
early  in  September,  considerable  numbers  of  the  third  brood  wTould 
fail  to  mature  before  fruit  picking.  Reared  larvae  of  this  brood 
began  to  mature  September  2,  and  the  band  record  for  1907  (p.  23) 
also  shows  an  increase  about  this  time.  The  calculated  time  of 
maturing  of  the  earliest  third-brood  larvae  in  1908  is  August  20. 
Owing  to  the  dropping  of  the  fruit  in  1908,  the  band  record  for  this 
season  (p.  24)  does  not  include  a  normal  number  of  the  later  larvae. 
In  1907  larvae  spun  cocoons  under  the  bands  as  long  as  any  apples 
were  on  the  trees,  and  at  harvest  time  many  small  worms  were  still 
in  the  fruit. 


THE   CODLING  MOTH   IN   THE   OZAKKS. 


19 


Forty-one  third-brood  larvae,  hatching  August  14  and  reared  in 
picked  fruit  in  jars  out  of  doors,  required  from  19  to  32  days  to 
become  full  grown,  the  average  being  slightly  over  24  days.  These 
records  are  given  in  Table  XXI. 

Table  XXI. — Life  of  third-brood  larvae,  reared  in  picked  fruit  in  jars  out  of  doors,  from 
eggs  recorded  in  Table  XIX. 


Number 
of  larvae. 

When  hatched. 

Date  of 

leaving 

fruit. 

Time  in 
fruit. 

Days. 

2 

Aug.  14,  a.m.. 

Sept.    2 

19 

2 

do 

Sept.   3 

20 

1 

do 

Sept.   4 

21 

3 

do 

Sept.   5 

22 

8 

do 

Sept.   7 

24 

3 

do 

Sept.   8 

25 

2 

do 

Sept.   9 

26 

1 

do 

Sept.  11 

28 

1 

do 

Sept.  12 

29 

1 

do 

Sept.  14 

31 

1 

do 

Sept.  15 

32 

1 

Aug.  14,  night. 

Sept.   3 

19 

2 

do 

Sept.   4 

20 

2 

do 

Sept.   5 

21 

1 

do 

Sept.    6 

22 

3 

do 

Sept.   7 

23 

2 

do 

Sept.   8 

24 

1 

do 

Sept.  11 

27 

1 

do 

Sept.  12 

28 

2 

do 

Sept.  14 

30 

1 

do 

Sept.  15 

31 

Total  number,  41. 

All  reared  larvae  of  the  third  brood  were  of  the  wintering  gener- 
ation. 

WINTERING   LARVAE. 

A  few  erratic  larvae  maturing  early  in  the  season  failed  to  pupate. 
They  remained  in  their  cocoons  throughout  the  season,  apparently 
in  a  perfectly  healthy  condition.  The  first  of  these  left  the  fruit 
June  9  and  was  undoubtedly  of  the  first  brood.  Two  others  leaving 
the  fruit  July  2  and  4  were  also  probably  of  this  brood.  One  win- 
tering larva  left  the  fruit  July  10,  two  July  19,  and  one  August  2. 
All  the  above  larvae  were  from  collected  wormy  fruit.  Among  20 
of  the  earlier  second-brood  larvae  reared  in  bagged  fruit  (Table  XXVI), 
1  wintering  larva  left  the  fruit  July  19.  In  1907,  out  of  41  second- 
brood  larvae  reared  in  the  laboratory  (Table  XXIX),  5  that  did 
not  pupate  left  the  fruit  August  1-6. 

Beginning  August  20,  the  percentage  of  wintering  larvae  leaving 
the  fruit  suddenly  arose  to  include  the  majority.  In  1907  this  hap- 
pened about  the  same  time.  A  record  of  the  material  collected  in 
taking  the  band  records  at  this  period  will  illustrate  the  transition. 
This  is  shown  in  Tables  XXII  and  XXIII. 


20  DECIDUOUS   FRUIT   INSECTS  AND   INSECTICIDES. 

Table  XXII.--  Transition  to  wintering  larvae,  in  1907. 


Larva;  forming  cocoons  under  bands. 


Number 
pupat- 
ing. 


Number 
winter- 
ing. 


July  22-29 

July  29-August  5 

Augusts  ia 

August  12-M 

August  19-26 

August  36-Septamber  •_• 
September  a  ;» 


112 
193 

144 
121 
60 


TABLE  XXIII . — Transition  to  wintering  larvae  in  1908. 
[From  record  made  by  Mr.  S.  W.  Foster.] 


Larva;  forming  cocoons  under  bands. 


Number 
pupat- 
ing. 


Number 

winter- 
ing. 


July  13-20 

July  20-27 

July27-August3 

August  3-10 

August  10-17 

August  17-24 

August  24-31 

August  31-September  7 


After  September  1  all  larvae  appearing  under  bands  were  of  the 
wintering  brood.  While  some  of  the  later  second-brood  larvae  may 
go  over  winter,  there  is  evidence  that  most  of  them  produce  a  second 
brood  of  moths  instead.  The  species  is  therefore  dependent  largely 
upon  the  third-brood  larvae  to  perpetuate  itself  from  season  to 
season. 

Conditions  affecting  wintering  larvae  in  the  orchard  were  not 
observed.  Around  the  out  door  apple  bin  at  a  vinegar  factory  where 
large  numbers  of  cocoons  were  examined  in  March  and  April  the 
great  majority  of  them  contained  live  larvae  or  pupae. 


REVIEW   OF   REARING   WORK   OF   THE    SEASON. 

An  effort  was  made  to  rear  through  the  season  a  continuous  line 
of  pedigreed  stock  from  the  earliest  spring  moths,  with  the  principal 
object  of  ascertaining  the  maximum  number  of  generations.  With 
the  exception  of  one  unimportant  break  early  in  the  season,  this 
program  was  successfully  carried  out. 

The  start  was  made  from  a  number  of  eggs  collected  in  the  field 
and  hatching  May  4,  several  days  before  the  hatching  of  the  first 
eggs  laid  in  cages.  The  larvae  were  reared  in  bagged  fruit  on  trees, 
and  developed  into  first-brood  adults  as  shown  in  Table  XXIV. 


THE   CODLING   MOTH   IN    THE   OZAKKS. 


21 


Table  XXIV. — Records,  from  hatching  of  egg  to  emergence  of  adult,  of  4  individuals  of 
the  first  generation.     (Reared  from  first  eggs  found  in  orchard.) 


Egg 
hatched. 

Larva  left 
fruit. 

Larva 
pupated. 

Moth 
emerged. 

May  4.... 

Do 

Do 

Do 

May  26 
May  27 
May  28 
May   29 

May   30 
May  31 
June    1 
June    2 

June    8 
June    9 
June  13 
June  12 

Not  enough  adults  were  obtained  in  this  rearing  to  insure  oviposi- 
tion  for  the  second  generation,  so  other  adults  reared  from  the  earliest 
wormy  apples  from  the  orchard  were  put  into  the  cage.  This  is  the 
only  break  in  the  line  of  descent,  where  outside  material  had  to  be 
added.  However,  there  can  be  no  doubt  that  all  these  moths  were 
of  the  first  brood.  In  Table  XXV  is  given  the  record  of  oviposition 
of  these  moths. 

Table  XXV. — Life  of  moths  of  first  brood,  reared  from  first-brood  larvx  from  earliest 
wormy  apples  collected  in  orchard,  and  from  earliest  larvx  reared  in  bagged  fruit. 


Moths  emerged  and  put  into  cage. 

Eggs  laid  (at  night). 

Moths  died. 

Date. 

Number. 

Date. 

Number. 

Date. 

Number. 

1 
1 

1 
5 
2 
11 

June  13 

2 
16 
26 
18 
104 
25 

June  16 

1 

June  14 

June  18 

1 

June  15 

June  19 

7 

June  12 

j  June  16 

June  21 

7 

June  17 

Escaped 

5 

1  June  18 

While  not  the  earliest,  the  eggs  laid  on  the  night  of  June  17  were 
selected,  on  account  of  their  numbers,  to  start  the  second  generation. 
Some  of  the  larvae  hatching  from  these  eggs  were  put  on  bagged  fruit, 
and  others  were  reared  in  picked  fruit  kept  out  of  doors  in  jars. 
Those  on  bagged  fruit  developed  as  shown  in  Table  XXVI. 

Table  XXVI. — Records,  from  oviposition  to  emergence  of  adult,  of  20  individuals  of  the 
second  generation,  reared  from  moths  recorded  in  Table  XX  V — larvx  reared  in  bagged 
fruit  on  trees. 


Individual  No. 

Egg 
hatched 

(at 
night). 

Larva 
trans- 
ferred to 
bagged 
fruit. 

Larva  left 
fruit. 

Larva 
pupated. 

Moth 
emerged. 

1 

June  22 
...do 

June  25 

...do 

...do 

July     13 
July     14 
...do 

July     24 
July     17 
July     28 
. . .  do . . 

Aug.    2 
July  27 
Aug.    6 
Aug.    7 
Aug.  10 
Aug.    7 
Aug.    3 
Do 

2 «. 

3 

...do 

4 

...do 

...do 

...do 

...do... 

5 

...do 

...do 

July     31 
July     29 
July     25 

6 

...do 

...do 

July     15 
July     16 

7 

...do.... 

...do.... 

8 

...do.... 

...do 

...do 

...do 

...do 

...do.  . 

9 

...do.... 

...do 

...do 

July     17 
July     18 

...do 

July     19 
July     20 
July     23 

July     22 
July     28 
Aug.      2 
July     22 
July     26 

...do 

Aug.      7 

July  30 
Aug.    7 
Aug.  11 
July  31 
Aug.    4 
Aug.    3 
Aug.  18 
Aug.  10 
Aug.     4 
Do. 

10 

11 

12 

...do 

...do 

...do.... 

13 

14 

15 

16 

...do 

...do 

...do 

.  do 

...do 

...do..... 

...do..... 

do 

17 

18 

...do 

...do 

...do 

...do.... 

Transformed  in  fruit, 
do 

19 

20 

...do 

...do 

do 

do 

July       19   1               Win* 

Aug.    5 
ering. 

1         

22 


DECIDUOUS   FRUIT    INSECTS   AND    INSECTICIDES. 


To  secure  third-brood  eggs,  only  moths  that  developed  from  the 
second-brood  larvaB  on  bagged  fruit  were  used.  These  emerged  and 
oviposited  as  recorded  in  Table  XXVII. 

TABLE  XXVII. — Lift  of  moths  of  second  brood,  reared  from  material  recorded  in 

Table  XXVI. 


Moths  emerged  and  put  into  cage. 

Eggs  laid  (at  night). 

Moths  died. 

Date. 

Number. 

Date. 

Number. 

Date. 

Number. 

July  30 

1 

1 
3 
2 

1 
3 

August  5 

2 
2 

55 
54 

August  9 

(female)  1 
(female)  1 
(female)  2 
(female)  2 
(male)  1 
(male)  1 

July  .'il 

August  6 

August  10 

August  8 

August  11 

August  9 

August  12 

Do 

August  13 

Lost  or  escaped 

Total  

13 

5 

The  eggs  laid  August  8  and  9  developed  a  third  brood  of  larvae  as 
shown  in  Table  XXVIII. 

Table  XXVIII. — Life  of  larvae  of  third  brood,  reared  from  eggs  recorded  in 

Table  XXVII. 


Eggs  laid 
(at  night). 


Aug.  8.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 
Aug.  9.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 

Do.. 


Eggs  hatched. 


Aug.  14, a.m... 

do 

do 

do 

do 

do 

do 

....do 

do 

do 

do 

Aug.  14,  night. 

do 

do 

do 

do 

do 

do 

do 

do 

do 


Number 

Larvae  left 

of  larvae. 

fruit. 

2 

Sept.    2 

2 

Sept.   3 

1 

Sept.    4 

3 

Sept.    5 

8 

Sept.    7 

3 

Sept.    8 

2 

Sept.    9 

1 

Sept.  11 

1 

Sept.  12 

1 

Sept.  14 

1 

Sept.  15 

1 

Sept.   3 

2 

Sept.   4 

2 

Sept.   5 

1 

Sept.   6 

3 

Sept.    7 

2 

Sept.    8 

1 

Sept.  11 

1 

Sept.  12 

2 

Sept.  14 

1 

Sept.  15 

The  above  larvae  were  reared  out  of  doors  in  picked  fruit, 
them  were  of  the  wintering  generation. 

THIRD    GENERATION    IN    1907. 


All  of 


In  1907  all  the  rearing  was  done  in  the  laboratory.  The  first  larvae 
and  pupa  collected  in  taking  the  band  record  (first  generation)  were 
used  to  begin  roaring  for  a  third  generation.  From  this  material 
first-brood  moths  began  to  emerge  June  25.  Second-brood  eggs  were 
laid  by  thorn  in  large  numbers  July  5  to  20,  from  which  41  second- 
brood  larvae  developed  as  shown  in  'Pablo  XXIX. 


THE    CODLING   MOTH    IX    THE   OZAEKS. 


23 


Table  XXIX. — Records  of  41  individuals  of  the  second  generation,  reared  in  the  labora- 
tory in  1907,  from  band-collected  larvse  and  pupae  of  the  first  generation. 


Number  of 

Eggs 

Larvae 

Moths          Number  of       Eggs 

Larvae 

Moths 

individuals. 

hatched. 

left  fruit. 

emerged.      individuals,  hatched. 

left  fruit. 

emerged. 

1 

July  10 

July  27 

Aug.  15.                     2 

July  15 

Aug.    3 

Aug.  15. 

1 

...do 

...do 

Aug.  12. 
Do. 

...do 

...do 

Aug.  16. 

2 

...do 

July  29 

...do 

...do 

Do. 

1 

...do 

Julv  30 

Pupa  died. 

...do 

...do 

Sept.  16. 

1 

July  15 

...do 

Aug.  15. 

...do 

Aug.    4 

Aug.  17. 

1 

...do 

July  31 

Aug.  13. 



...do 

Aug.  16. 

1 

...do 

...do 

Aug.  14. 

...do 

Wintering. 

5 

...do 

Aug.    1 

Do. 



...do 

Aug.  15. 

1 

...do 

...do 

Aug.  16. 

July  15 

Aug.    5 

Sept.  1. 

1 

...do 

...do 

Do. 

...do 

...do 

Wintering. 

1 

---do 

...do 

Aug.  25. 

1          ---do 

Aug.    6 

Do. 

3 

...do 

Aug.    2 

Aug.  15. 

1          ...do 

...do 

Do. 

1 

...do 

...do 

Aug.  21. 
Aug.  22. 

1 

Aug.     7 
...do 

Aug.  18. 
Aug.  20. 

1 

...do 

...do 

1 

1 

...do 

Aug.     1 
Aug.    2 

W  intering. 
Aug.  27. 

1 

Aug.    9 

Aug.  25. 
Aug.  15. 

1 

...do 

2         1  July   15 

a  Pupated  in  fruit. 

As  indicated  in  the  table,  5  of  these  larvse  lived  over  winter,  while 
the  others  developed  to  second-brood  moths.  Xo  attempt  was 
made  to  secure  third-brood  eggs  from  these  moths,  but  from  the  time 
of  their  emergence  we  should  expect  third-brood  larvae  to  begin 
hatching  about  August  20. 

MISCELLANEOUS  OBSERVATIONS. 
BAND   RECORDS. 

A  band  record  is  an  important  aid  in  tracing  the  seasonal  history 
of  the  codling  moth.  The  band  record  for  1 907  is  given  in  Table  XXX 
and  is  shown  graphically  in  figure  2. 

Table  XXX. — Band  record  of  1907,  made  from  25  trees  in  an  unsprayed  orchard. 


Date. 


June  3. 
June  10 
June  17 
June  24 
July  1 . 
July  8. 
July  15. 
July  22. 
July  29. 


Number 

of  larvae 

and  pupae 

taken 

from 

bands. 


0 
0 
28 
48 
25 
47 
56 
75 
131 


Date. 


Augusts 

August  12 

August  19 

August  26 

September  2 . 
September  9. 
September  16 
October  7 


Number 
of  larvae 
and  pu- 
pae taken 
from 
bands. 


212 
168 
170 
98 
46 
52 
67 
156 


The  gap  between  the  first-brood  and  the  second-brood  larvae, 
indicated  in  the  1907  band  record  at  July  1,  should  have  come  a  week 
or  more  later.  The  week  ending  July  1  was  cool  and  very  rainy,  the 
bands  being  continuously  wet.  This  must  have  delayed  many 
larvse  in  leaving  the  fruit,  and  prevented  others  from  selecting  the 
bands  as  a  place  for  spinning  their  cocoons. 
30490°— Bull.  80—12 3 


24 


DECIDUOUS   FRUIT  INSECTS  AND   INSECTICIDES. 


The  third  brood  shown  in  the  1907  band  record  (beginning  Sep- 
tember 2)  is  probably  normal  in  bulk,  though  the  curve  should  per- 
haps rise  more  abruptly  and  stop  earlier  at  the  date  of  harvesting 
the  apples.  There  were  taken  October  7  from  the  bands  156  larvae, 
an  average  of  52  per  week  since  the  last  previous  examination ;  mean- 
while the  fruit  had  been  gathered,  but  the  exact  date  could  not  be 
ascertained.  Picking  the  fruit  would  of  course  put  an  end  to  the 
band  record. 

It  will  be  noticed  in  the  curve  (fig.  2)  that  the  second  brood  is  many 
times  larger  than  the  first.  But  the  third  brood,  instead  of  showing 
a  further  increase,  is  scarcely  larger  than  the  first.  This  is  not  to  be 
taken  as  evidence  of  only  a  partial  brood,  but  is  due  to  the  fact 
that  the  fruit  was  harvested  before  the  bulk  of  the  third  brood  had 
matured. 


Fig.  2.— Curve  showing  record  of  larvae  and  pupae  of  the  codling  moth  taken  from  bands  in  1907. 

The  1908  band  record  (Table  XXXI  and  fig.  3)  was  influenced  by 
the  very  smal1  size  of  the  apple  crop  in  that  year. 


Table  XXXI.— Band  record  of 1908,  made  from  18  trees  in  an  orchard  sprayed  once  after 

the  calices  had  closed. 

[Record  by  Mr.  S.  W.  Foster.] 


June  6-15 
June 22.. 
June  29.. 
July  6... 
July  13.. 
July  20.. 
July  27.. 


The  trees  from  which  this  record  was  made  had  lost  all  their  fruit 
by  September  7. 


THE   CODLIXG   MOTH   IN   THE   OZARKS. 


25 


In  the  1908  band  record  the  smaller  size  of  the  second  brood  as 
compared  with  the  first  is  due  to  the  fact  that  the  very  small  crop  of 
apples  became  so  infested  that  they  fell  from  the  trees  before  a  large 
number  of  the  later  larvae  had  matured.     For  the  same  reason  the 


Fig.  3. — Curve  showing  band  record  of  1908. 

third  brood  is  not  represented.  The  record  was  not  begun  in  time 
to  include  the  earliest  larvae,  which  had  begun  to  leave  the  fruit 
May  24. 

A  band  record  made  in  1908  by  Mr.  F.  TV.  Faurot  (figs.  4  and  5) 
at  Anderson,  Mo.,  40  miles  north  of  Siloam  Springs,  is  interesting 


June  June 
tz        20 


June 
30 


Ji 


July    July    Julu    Jiua,       .Jtua    Jlua.JJua.    Jluax 

n*    \dr    z?    i*      io     /6     zi    zr 


Fig.  4.— Curve  showing  band  record  from  6  Jonathan  apple  trees,  made  at  Anderson,  Mo.,  in  1908,  by- 
Mr.  P.  W.  Faurot. 

as  showing  the  effect  of  spraying.  The  record  was  made  on  un- 
sprayed  trees  in  a  sprayed  orchard.  Since  the  banded  trees  were 
themselves  not  sprayed,  the  size  of  the  first  brood  of  larvae  shown 
in  the  band  record  was  not  affected.  But  the  spraying  of  the  re- 
mainder of  the  orchard,  and  the  killing  of  all  larvae  and  pupae  taken 


26 


DECIDUOUS  FRUIT  INSECTS  AND   INSECTICIDES. 


from  the  bands,  caused  a  marked  reduction,  instead  of  the  normal 
increase,  in  the  size  of  the  second  brood. 

The  part  of  this  record  from  6  Jonathan  trees,  from  which  the  fruit 
was  picked  the  last  of  August,  thus  shutting  out  the  third  brood,  is 
separated  from  the  remainder.  Figure  4  shows  the  record  from  these 
trees,  and  figure  5  the  remainder  of  the  record,  taken  from  5  Gano 
and  9  Lansingburg  trees,  the  latter  a  very  late  variety. 


Fig.  5.— Curve  showing  band  record  from  14  Gano  and  Lansingburg  apple  trees,  made  at  Anderson,  Mo., 

in  1908,  by  Mr.  P.  \V.  Faurot. 

EMERGENCE   OF   MOTHS. 

All  larvaa  and  pupae  collected  in  taking  the  band  records  at  Siloam 
Springs  were  kept  in  muslin-covered  jars,  in  order  to  record  the  issu- 
ing of  adults.  The  material  of  1907  was  kept  in  the  laboratory,  and 
that  of  1908  out  of  doors.  Weekly  summaries  of  the  emergence  of  the 
moths  are  given  in  Tables  XXXII  and  XXXIII  and  in  figures  6  and  7. 

Table  XXXII. — Laboratory  record  of  emergence  of  adults  from  material  collected  in 

taking  band  record  in  1907. 


June28-July  4.. 

July  4-11 

July  11-18 

July  18-25 

July  25- August  1 

August  1-8 

August  8-15 


August  1.5-22 

August  22-29 

August  29-September  5 

September  5-12 

September  13-19 

September  20 

October  4 


TABL1  XXXIII. — Outdoor  record  of  emergence  of  adults  from  material  collected  in 
taking  band  record  in  1908. 

[Records  by  Mr.  S.  W.  Foster.] 


Date. 


Number 

of  moths 
emerging. 


June  22-29 18 

I  July  6 43 

July  6-13 40 

July  13-20 38 

July  20-27 40 

Jul v  27-August  3 


Date. 


August  2-8 

August  8-15 

August  15-22 

August  22-29 

August  29-Scptember  5. 
September  5-12 


Number 
of  moths 
emerging. 


THE  CODLING  MOTH  IN  THE  OZAEKS. 


27 


It  will  be  noticed  that  the  curves  illustrating  the  emergence  records 
follow  closely  the  contour  of  the  corresponding  band-record  curves, 
as  far  as  the  first  and  the  second  broods  are  concerned.  The  third 
brood  is,  of  course,  not  represented  in  the  emergence  records.  A 
record  of  the  emergence  of  the  third  brood  of  1907  (spring  brood  of 
1908)  is  given  on  page  5,  figure  1. 


June  July    July    July    July    /lug.  flug.    /lug.  /lug.    Jug.  Sept.    Sept.  Sept.  Sept.    Oct 
28         A  II  taJ      25  lJ       Q*       I57      Z?       2^       S  \2  if         z£         / 


Fig.  6.— Curve  showing  emergence  of  adults  from  material  collected  in  taking  band  record  in  1907. 

The  ratio  in  size  of  the  second  brood  of  adults  to  the  second  brood 
of  larvae  is  practically  the  same  as  between  the  first-brood  adults 
and  the  first-brood  larvae,  shown  in  the  emergence  and  the  band 
records,  respectively.  This  shows  that  as  large  a  proportion  of  the 
second-brood  as  of  the  first-brood  larvae  transform  to  adults;  which 
is  evidence  that  there  is  nearly  a  full  third  brood. 


June—Jur?e~Julu   July  Julu    Julu  Aug.  /lug.  /lug.   /Jug.  /lug.    Sept.  Sept. 
22       Z%       6\       13        20      zr       3         a        13        zz      21        S        IZ 


Fig.  7.— Curve  showing  emergence  of  adults  from  material  collected  in  taking  band  record  in  1908. 
LARVAE    OX    FOLIAGE. 

Two  larvae  just  hatched  were  inclosed  in  paper  bags  on  water 
sprouts  May  4.  The  twigs  were  not  examined  again  until  May  29. 
In  each  case  there  was  evidence  of  work  by  the  larvae.  On  one  twig 
the  feeding  was  confined  to  a  leaf,  but  on  the  other  four  the  young 
larvae  had  bored  down  the  tender  end  of  the  sprout  from  half  an  inch 
to  2  inches.     No  remains  of  the  larvae  could  be  found.     They  had 


28 


DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


apparently  bored  down  the  twigs  until  they  encountered  wood  too 
hard  for  them  to  chew,  when  they  left  the  burrows  and  were  lost. 
In  the  laboratory  four  larvae  just  hatched  were  put  on  foliage 
.May  7.  The  ends  of  the  twigs  were  stuck  into  a  bottle  of  water, 
cotton  was  stuffed  around  the  neck  of  the  bottle,  and  the  whole  put 
under  a  bell  jar.  Two  larvae  were  working  May  12.  On  May  23 
one  larva  was  still  feeding.  It  had  begun  work  on  a  leaf,  then  it 
bored  into  the  midrib  and  through  the  petiole  into  the  end  of  the 
twig.  The  larva  was  transferred  to  a  fresh  twig,  and  when  again 
examined,  May  29,  had  burrowed  for  a  distance  of  1}  inches.  Then 
it  had  left  the  burrow,  and  forcing  its  way  through  the  cotton  at  the 
neck  of  the  bottle  had  drowned  itself  therein.  It  had  reached  a 
length  of  9.5  millimeters  and  appeared  to  have  passed  the  fifth  molt. 

LARV.E    IN    PEACHES. 

Two  peaches  containing  codling-moth  larvae  were  collected  in  the 
orchard,  on  trees  adjoining  an  apple  orchard.  Both  peaches  ripened 
several  days  before  the  larvae  left  them.  One  larva  issued  July  28 
from  a  peach  collected  July  10.  The  adult  emerged  August  10. 
Another  peach  collected  July  29  gave  out  a  larva  on  August  2,  from 
which  the  adult  emerged  August  16. 


NUMEROUS    LARV.E    IN   ONE    APPLE. 

Throughout  the  season,  and  also  in  1907,  it  was  noticed  that  when 
large  numbers  of  young  larvae  were  allowed  to  enter  a  single  apple 
at  the  same  time,  only  a  few  survived.  If  larvae  being  reared  from 
eggs  laid  in  cages  were  not  transferred  to  separate  fruits  within  three 
to  five  days  after  hatching,  or  before  their  burrows  reached  the  core, 
only  a  small  proportion  of  the  number  entering  could  be  accounted 
for. 

Some  third-brood  larvae  entering  fruit  in  cages  were  left  undis- 
turbed, the  apples  being  kept  in  jars  out  of  doors.  The  results, 
given  in  Table  XXXIV,  show  that  more  than  one  larva  is  not  likely 
to  reach  maturity  in  a  single  fruit  at  the  same  time. 

Table  XXXIV. — Record  of  maturing  larvx  from  4  apples,  each  infested  at  the  same 

time  by  numerous  larvae. 


hatched. 

Number 

of  larvae 

entering 

apple. 

Larvae  formed 
cocoons. 

Number 

of  larvae 

Date. 

Number. 

maturing. 

Aug.  14.. 
Do 

Sept.  14.. 

18 
11 
18 
8 

Sept     5 
(Sept.  5; 
spun  co- 
coon in 
fniit. 
Oct.    20 
...do.... 

1 

1 
1 

1 
1 

1 

}   » 

1 
1 

THE    CODLING   MOTH    IX    THE   OZARKS. 


29 


NUMBER    OF    MOLTS. 

A  large  number  of  larvae  were  reared  separately  in  pieces  of  apple 
in  vials.  Immediately  after  hatching  they  were  transferred  to  the 
vials,  and  were  examined  daily,  or  at  least  every  second  day.  At 
each  examination  they  were  changed  to  fresh  food. 

Either  the  frequent  disturbance  or  the  lack  of  apple  seeds  in  their 
diet  caused  the  larvae  to  develop  very  slowly  and  to  become  dwarfed. 
The  mature  larvae  were  very  much  undersized,  and  some  of  the  moths 
that  developed  from  them  were  scarcely  larger  than  adults  of  the 
lesser  apple  worm  (Enarmonia  prunivora  Walsh). 

The  normal  number  of  molts  is  apparently  6  (7  instars),  though 
3  of  the  12  larvae  that  reached  maturity  molted  7  times  (8  instars). 
The  period  of  development  was  so  much  lengthened  and  the  larvae 
were  so  dwarfed  that  no  conclusions  can  be  given  as  to  the  normal 
length  of  the  various  instars  or  the  size  of  the  larva  in  each. 

In  Table  XXXV  are  given  the  individual  records  (omitting  meas- 
urements) of  the  12  larvae  that  reached  maturity. 

Table  XXXV. — Number  of  molts  of  the  codling  moth — laboratory  observations  on 
larvse  reared  in  pieces  of  apple  in  vials. 


Individual 
Xo. 


Molts. 


When 
hatched. 


II. 


Aug. 
..do. 
..do. 
..do. 
..do. 
..do. 


HI. 


IV. 


17  !  Aug.  21  I Sept 

Aug.  28  Sept 
Aug.  29  ' 


Aug. 

..do. 
..do. 
..do. 


Aug.  23 

..do 

Aug.  24 
Aug.  23 
Aug.  24 
Sept.  9  J  Sept.  14 

...do L..do 

Sept.  8  i  Sept.  15 

Sept.  9  ...do 

Sept.  8  Sept.  13 


Aug.  29 
Aug.  28 
Aug.  29 


Sept. 
Sept. 
Sept. 
Sept. 
Sept. 
Sept. 


Sept.  20 


Sept.  9 
Sept.  7 
Sept.  10 
Sept.  8 
Sept.  11 
Sept.  8 
Sept.  10 
Sept.  29 
Oct.  2 
Sept.  29  I  Oct 
Oct.  2  Oct 
Sept.  28  ...do.. 


Sept.  16 
Sept.  14 
Sept.  16 
Sept.  19 
Sept 
...do 
Sept 
Oct. 
Oct. 


17 


VI. 


Sept,  26 
Sept.  21 
Sept.  27 


Sept.  27 
Sept.  30 
Oct.  3 
Oct 
Oct 
Oct 


15  !  Oct. 
Oct. 


VII. 


Oct.    19 


Nov. 

Nov. 


Larva 
formed 
cocoon. 


Oct.  13 
Oct.  6 
Oct.  15 
Oct.  7 
Oct.  16 
Oct.  26 
Oct.  21 
Dec.  4 
Dec.  2 
Nov.  20 
Nov.  27 
Nov.  17 


NATURAL    ENEMIES. 


On  May  6,  while  bagging  fruit  and  collecting  codhng-moth  eggs, 
about  a  dozen  specimens  of  a  red  mite  (determined  by  Mr.  X.  Banks  as 
Trombidium  sp.)  were  observed  crawling  about  the  twigs  and  leaves. 
By  accident  one  of  them  got  into  the  box  of  collected  codhng-moth 
eggs  on  leaves.  On  examining  the  eggs  in  the  laboratory  later,  the 
mite  was  found  in  the  act  of  eating  one  of  them.  The  egg  upon 
which  it  was  operating  was  in  the  black-spot  stage.  When  the  mite 
had  finished,  the  egg  had  the  appearance  of  having  hatched,  except 
that  the  black  head  and  cervical  shield  of  the  embryo  remained  visible 
underneath  the  egg  shell.  The  mite  was  then  allowed  to  attack  a 
larva  that  was  just  issuing  from  the  egg,  having  crawled  nearly  all  the 


30  DECIDUOUS   FRUIT   INSECTS  AND   INSECTICIDES. 

way  out.  When  examined  three  hours  later,  nothing  was  left  of  the 
larva  but  the  head  and  shriveled  skin.  This  mite  was  later  found  to 
be  fairly  common  on  other  trees  as  well  as  apple. 

Two  species  of  ants,  Solenopsis  validiusculus  Emery  and  Cremasto- 
gaster  bicolor  Buckley  as  determined  by  Mr.  Theo.  Pergande,  were 
frequently  found  attacking  live  larvae  under  bands. 

An  ichneumon,  determined  by  Mr.  J.  C.  Crawford  as  the  commonly 
recorded  parasite  of  the  codling  moth,  Pimpla  annulipes  Brulle, 
was  frequently  reared  from  band-collected  material.  From  one  lot  of 
larvae  taken  from  the  bands,  Mr.  S.  W.  Foster  reared  11  specimens  of 
an  undetermined  chalcidid,  possibly  a  secondary  parasite. 

Two  specimens  of  a  small  tachina  fly,  Tachinophyto  sp.?  (deter- 
mined by  Mr.  C.  H.  T.  Townsend),  were  reared  in  1907.  One  indi- 
vidual issued  from  a  larva  which  was  brought  into  the  laboratory 
while  still  in  the  apple,  though  nearly  full  grown. 

PERCENTAGE    OF    FRUIT    INFESTED. 

In  1908  the  apple  crop  was  so  small  that  the  growers  did  not  con- 
sider it  worth  protecting  by  spraying.  On  account  of  the  small  crop 
and  the  lack  of  preventive  measures,  practically  every  apple  was 
wormy  and  the  fruit  fell  from  the  trees  before  a  large  number  of  the 
later  larvae  had  a  chance  to  enter.  In  1907,  counts  from  8  unsprayed 
trees  (4  Ben  Davis  and  4  Winesap)  showed  a  percentage  of  wormy 
fruit  varying  from  48.1  to  64.1,  the  average  on  the  Winesaps  being 
50.7  and  on  the  Ben  Davis  60.4.  A  total  of  20,890  apples  were  exam- 
ined from  the  8  trees,  including  all  windfalls  throughout  the  season. 
Apples  infested  with  codling  moth,  Enarmonia  prunivora  Walsh,  and 
Epinotia  pyricolana  Murtfeldt  were  classed  together  as  "wormy" 
fruit.     Curculio  injury  was  disregarded. 

So  small  a  percentage  of  infestation  seems  rather  remarkable  in  a 
locality  such  as  this,  where  at  least  a  majority  of  the  insects  pass 
through  three  generations,  while  in  other  fruit-growing  districts  with 
a  shorter  season  an  unprotected  apple  crop  is  completely  destroyed 
by  the  codling  moth.  Perhaps  the  third  generation  may  be  a  dis- 
advantage in  the  increase  of  the  insect,  as  a  considerable  proportion 
of  this  brood,  being  yet  in  the  fruit  when  the  crop  is  harvested,  is 
removed  from  the  orchard  (see  1907  band  record,  p.  23).  And  it 
must  be  that  many  of  the  later  larvae  to  hatch  would  even  fail  to 
find  any  fruit  to  enter,  as  the  apple  harvest  usually  begins  early  in 
September. 


THE   CODLING   MOTH   IX   THE   OZARKS.  31 

CONCLUSIONS. 

Three  generations  of  larvae  of  the  codling  moth  occur  in  the  Ozarks 
of  northern  Arkansas,  and  most  of  the  members  of  the  second  gen- 
eration develop  into  adults. 

The  date  at  which  larva?  begin  to  enter  the  fruit,  relative  to  the 
blossoming  of  apple  trees,  is  susceptible  to  great  variation  on  account 
of  weather  conditions.  In  the  two  seasons  under  observation  the 
interval  was  6  and  3  weeks,  respectively,  between  the  falling  of 
apple  blossoms  and  the  hatching  of  the  first  larvae. 

There  is  a  sufficient  interval  between  the  first  brood  and  the  sec- 
ond brood  of  larvae  to  be  noticeable  in  the  field;  so  that  members 
of  the  two  broods,  though  present  together,  may  be  distinguished 
by  their  size  in  most  cases. 

The  third  brood  of  larvae  constitutes  the  greater  part  of  the  winter- 
ing brood.  Since  the  principal  varieties  of  apples  are  harvested  in 
this  region  while  considerable  numbers  of  the  third  brood  of  larvae 
are  yet  immature,  the  number  of  larvae  wintering  in  the  orchard  is 
materially  reduced.  A  smaller  percentage  of  fruit  is  infested  by  the 
codling  moth  in  this  locality  than  in  many  places  where  only  two 
generations  are  developed. 

A  summary  of  the  seasonal  history  of  the  insect  for  the  year  1908, 
as  detailed  in  the  preceding  pages,  is  shown  diagrammatic  ally  in 
figure  8. 


32 


DECIDUOUS   FRUIT   INSECTS  AND   INSECTICIDES. 


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U.  S.  D.  A.,  B.  E.  Bull.  80,  Part  II.  D.  F.  1. 1.,  June  30.  1909, 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


THE  CIGAR  CASE-BEARER. 

{Coleophora  fletchereUa  Fernald.) 

By  A.  G.  Hammar. 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

INTRODUCTION. 

During  the  past  several  years  the  cigar  case-bearer  (Coleophora 
ftetcherella  Fernald)  has  occasionally  come  to  notice  on  account  of  the 
injuries  inflicted  by  it  on  the  foliage  and  fruit  of  apple  and  pear 
trees,  especially  the  former. 

Although  apparently  common  in  different  sections  of  the  country 
its  presence  is  readily  overlooked,  owing  to  its  small  size  and  the 
concealed  life  of  the  larva.  When  occurring  in  large  numbers  it  first 
attracts  attention  during  May  and  June,  at  which  time  the  insect  is 
most  active  and  feeding  freely  upon  the  foliage.  The  larva  itself  is 
in  a  small  cylindrical  or  cigar-shaped  case,  which  is  composed  of  a 
portion  of  the  skin  of  the  leaf. 

In  its  feeding  habits  the  larva  is,  to  a  certain  extent,  a  miner.  It 
always  carries  its  case  for  protection,  however,  protruding  from  it 
when  feeding.  Upon  close  observation  of  the  feeding  marks  on  the 
foliage  it  will  be  found  that  they  consist  of  a  more  or  less  round 
undermined  area,  from  which  the  parenchyma  has  been  removed,  with 
a  minute  circular  hole  through  the  skin  of  the  leaf,  through  which 
the  larva  made  its  entrance.  By  these  markings  on  the  leaves  and  by 
the  cigar-shaped  cases  (fig.  9)  of  the  larva  the  insect  is  readily  dis- 
tinguished from  other  related  orchard  pests.  The  cigar  case-bearer 
has  occasionally  proved  itself  capable  of  destroying  the  foliage  of 
entire  orchards.  Crop  failures  and  various  deformities  of  the  fruit 
have  also  been  ascribed  to  this  insect. 

HISTORY. 

The  attention  of  entomologists  was  first  called  to  the  destructive- 
ness  of  the  cigar  case-bearer  in  1888,  when  Mr.  P.  Barry,  of  Rochester, 
N.  Y.,  found  the  larvae  feeding  upon  the  young  fruit  of  pears.    Speci- 

33 


34  DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 

mens  of  the  insect  were  sent  to  Dr.  J.  A.  Lintner,  as  recorded  in  his 
Fifth  Report,  page  324  (1889).  Based  upon  the  information  and 
studies  of  the  living  material  received  from  Mr.  Barry,  Doctor  Lintner 
later  gave  an  account  of  the  insect  before  the  Western  New  York 
Horticultural  Society  in  1890,  under  the  title,  "A  New  Pear  Insect, 
Coleophora  sp.,"  with  a  brief  description  of  the  insect  and  its  life 
history  and  recommending  an  arsenical  spray  for  its  control  in  case  it 
should  appear  in  injurious  numbers.  Later  the  same  account  wTas  re- 
printed in  Popular  Gardening  for  1890,  and  in  1891  it  was  included 
in  Doctor  Lintner's  seventh  report  as  state  entomologist  of  New  York. 

About  the  same  time  as  noted  in  the  Rochester  occurrence,  the 
insect  attracted  attention  in  orchards  in  Canada.  Dr.  James  Fletcher 
in  1889  received  some  larvae  from  Charlestown,  Prince  Edward 
Island,  which  were  found  feeding  on  plum  trees.  Soon  after  they 
were  also  found  depredating  upon  apple  and  pear.  In  1891  Dr.  D. 
Young,  of  Adolphustown,  Ontario,  informed  Doctor  Fletcher  of 
their  abundance  in  orchards  of  that  locality,  and  during  the  same 
year  further  reports  of  the  insect  came  in  from  Port  Williams,  Nova 
Scotia.  At  Adolphustown  Doctor  Young  carried  out  extensive  spray- 
ing experiments  with  kerosene  emulsion  and  Paris  green.  A  full 
account  of  these  and  other  experiments  will  be  found  in  Fletcher's 
various  publications  from  1891  to  1894.  Prof.  C.  H.  Fernald,  in  1892, 
described  the  new  insect,  naming  it  fletcherella  in  honor  of  Doctor 
Fletcher,  who  had  submitted  specimens  for  determination.  He  also 
mentions  having  received  specimens  from  Lintner,  who,  in  his  ninth 
report  (1893),  showed  that  the  case-bearer  referred  to  in  his  earlier 
reports  was  this  same  species.  Further  notes  on  the  insect  in  Canada 
were  given  by  Fletcher  in  the  Report  of  the  Entomological  Society 
of  Ontario  for  1894. 

Prof.  L.  H.  Bailey  in  1895  reported  that  the  failure  of  the  apple 
crop  in  Wayne  and  Monroe  counties,  N.  Y.,  was  to  a  great  extent 
due  to  the  damages  caused  by  the  cigar  case-bearer.  The  same  year 
Professor  Slingerland  published  a  valuable  account  of  the  insect, 
giving  a  detailed  description  of  it  and  of  its  life  history,  with  excel- 
lent photographic  illustrations  and  a  full  bibliography. 

Prof.  T.  D.  A.  Cockerell  in  1896  reported  its  introduction  at  Santa 
Fe,  N.  Mex.,  the  young  larva?  evidently  having  been  brought  in  on 
infested  nursery  stock  from  the  State  of  New  York. 

A  hymenopterous  parasite,  Microdus  laticinctus  Ashm.,  was  ob- 
tained by  Fletcher  from  cases  from  Port  Hope,  Ontario.a 

In  1898  Faville  reported  the  occurrence  of  the  insect  at  Manhattan, 
Kan8.,  where  for  several  years  it  had  caused  much  injury. 

« Twenty-seventh  Ann.  Rep.  Bnt  Soc.  <>nt..  1897,  p.  GT. 


THE   CIGAB   CASE-BE AEER.  35 

A  brief  account  of  the  life  history  of  the  insect  is  given  by  Dr. 
E.  P.  Felt  in  the  Country  Gentleman  for  November,  1901,  and  it  is 
referred  to  by  the  same  writer  in  his  Illustrated  Descriptive  Cata- 
logue of  Some  of  the  More  Injurious  and  Beneficial  Insects  of  New 
York  State.0 

Prof.  S.  A.  Forbes  in  1900  gave  a  brief  note  on  a  similar  insect 
feeding  on  sugar  beet.  At  the  time  this  was  supposed  to  be  G.  fletch- 
erella  Fernald,  having  very  similar  habits  and  appearance.  Mr. 
August  Busck,  of  this  Bureau,  however,  has  recently  examined  speci- 
mens sent  by  Professor  Forbes  and  finds  that  they  belong  to  a  differ- 
ent species. 

In  1902  it  was  included  in  Banks?s  Principal  Insects  Liable  to  be 
Distributed  on  Nursery  Stock.5  It  is  here  recorded  feeding  upon 
pear  and  quince. 

Specimens  Avere  received  by  Doctor  Fletcher  from  Victoria,  British 
Columbia,  in  1905,  and  were  sent  by  him  to  this  Bureau  for  deter- 
mination. The  moths,  which  were  examined  by  Mr.  Busck,  were 
found  to  be  slightly  smaller  than  those  from  New  York  or  east- 
ern Canada.  Recently  Mr.  Busck  has  been  kind  enough  to  reexamine 
the  specimens,  and  from  a  comparison  of  later  collected  material  in 
the  United  States  National  Museum  collection  considers  those  from 
Victoria  to  be  identical.  The  larvae  of  the  moths  mentioned  above 
were  found  feeding  on  hawthorn.  The  difference  in  size  is  probably 
due  to  local  conditions  and  to  the  different  food  plant. 

In  a  letter  dated  February  16,  1909,  to  this  Bureau,  Prof.  R.  H. 
Pettit,  of  the  Michigan  Agricultural  College,  states  that  he  received 
specimens  of  the  cigar  case-bearer  from  Port  Hope,  Mich.,  where  in 
1908  it  was  reported  as  being  quite  a  serious  pest. 

During  the  summer  of  1908  the  writer  had  the  opportunity  of 
studying  the  cigar  case-bearer  at  North  East,  Pa.  A  small  orchard 
of  40  or  50  trees  belonging  to  Mr.  A.  L.  Short  was,  in  the  early  part 
of  June,  so  badly  infested  by  the  insect  that  literally  every  leaf  had 
been  devoured. 

Mr.  R.  W.  Braucher,  of  this  Bureau,  during  the  summer  of  1908 
observed  the  insect  at  Douglas,  Mich.,  where  it  was  found  more  or 
less  frequently  in  different  orchards. 

DISTRIBUTION. 

The  cigar  case-bearer  is  evidently  a  native  insect,  feeding  originally 
on  crab  apples  and  hawthorn.  Although  at  present  recorded  only 
from  scattered  sections  of  the  country,  it  is  not  improbable  that  it 
has  a  rather  general  distribution.     In  Canada,  Fletcher  reports  it 

a  Bull.  39,  N.  Y.  State  Mus.,  1900. 

6  Bull.  34,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  p.  38. 


36  DECIDUOUS   FRUIT   INSECTS  AND   INSECTICIDES. 

from  Ontario,  Quebec,  Nova  Scotia,  Prince  Edward  Island,  and  Brit- 
ish Columbia.  In  the  State  of  New  York  it  has  been  recorded  by 
Lintner,  Slingerland,  and  others;  at  Manhattan,  Kans.,  by  Faville; 
at  Santa  Fe,  X.  Mex.,  by  Cockerell ;  at  North  East,  Pa.,  by  the  writer; 
at  Port  Hope,  Mich.,  by  Pettit,  and  at  Douglas,  Mich.,  by  Braucher. 

FOOD    PLANTS    AND    INJURY. 

The  insect  has  a  rather  limited  list  of  food  plants.  Originally  it 
probably  fed  on  native  crab  apples  and  certain  species  of  Crataegus. 
With  the  extensive  planting  of  orchards,  it  has  found  in  apple  and 
pear  favorite  food  plants,  and  it  is  largely  to  these  two  fruits  that  its 
depredations  have  been  confined.  It  has  also  been  recorded  feeding 
upon  quince  and  plums,  and  will  undoubtedly  be  found  on  other  trees 
allied  to  them. 

Like  many  other  injurious  insects,  the  work  of  the  cigar  case-bearer, 
when  the  species  is  present  in  destructive  numbers,  comes  suddenly  into 
evidence.  The  caterpillars  infest  mainly  the  leaves,  but  in  the  spring 
they  may  also  be  found  on  the  buds  and  the  young  fruits.  Injury  at 
this  time  of  the  season  is  naturally  quite  important  as  affecting  both 
the  vigor  of  the  trees  and  the  development  of  the  fruit.  As  shown  in 
Plate  I,  figures  1  and  2,  the  foliage,  under  conditions  of  serious  infes- 
tation, becomes  practically  skeletonized.  In  the  orchard  at  Xorth 
East,  Pa>,  which  came  under  the  writer's  observation  in  1908,  the 
foliage  was  completely  devoured  and  withered  by  the  early  part  of 
June,  and  from  a  distance  appeared  brown  and  dead,  as  if  swept  by 
fire.  Neighboring  fruit  growers  believed  this  to  be  due  to  the  burn- 
ing effect  of  an  arsenical  spray,  but  as  a  matter  of  fact  the  orchard 
had,  to  the  knowledge  of  the  present  owners,  never  been  spra}Ted, 
When  inspected,  June  3,  the  larvae,  in  their  cigar-shaped  cases,  were 
found  in  such  great  numbers  that  not  only  had  the  foliage  been  com- 
pletely devoured,  but  the  tender  growths  of  the  branches  had  been 
very  generally  attacked.  (PL  I,  fig.  8.)  It  was  probabhy  owing  to 
lack  of  food  that  they  were  dropping  down  from  the  branches,  sus- 
pended by  a  silken  thread,  in  search  of  new  feeding  places.  The 
owner,  Mr.  A.  L.  Short,  and  his  team  at  the  time  of  plowing  the 
orchard  were  completely  covered  with  the  larvae  and  presented  a  very 
strange  sight.  In  looking  through  the  spaces  between  the  rows  of 
trees  one  was  impressed  with  the  abundance  of  the  larvse,  for  their 
cases  in  countless  numbers,  suspended  by  silken  threads  and  waving 
back  and  forth  in  the  breeze,  almost  resembled  a  drapery.  As  the 
Larvee  ceased  feeding  by  about  the  middle  of  June,  the  trees  put  out 
a  new  growth  of  leaves,  and  later  in  the  season  the  condition  of  the 
orchard  was  favorable  to  its  recuperation  from  the  attack. 


Bull.  80,  Part  II,  Bureau  of  Entomology.  U.  5.  Dept.  of  Agriculture. 


Plate  I. 


The  Cigar  Case-bearer  (Coleophora  fletcherella\ 

Fig.  L— Apple  leaf  with  larvae  at  work  (enlarged).  Fig.  2.— Infested  apple  twig,  two  week-  after 
larvae  ceased  feeding  |  reduced  |.  Fig.  3.— Young  branches  with  puncturelike  feeding  marks  of 
the  larvae  (natural  size).    (Original.) 


THE   CIGAE    CASE-BEAEEE.  37 

DESCRIPTION. 
THE   EGG. 

The  minute  egg  (fig.  10.  d).  which  is  hardly  visible  to  the  naked 
eye.  is  pale  yellow,  and  over  the  surface  is  closely  marked  with  ele- 
vated ridges.  On  the  average,  it  measures  0.31  by  0.25  mm.  and  is 
almost  round  in  outline. 

THE  LARVA  AND  ITS  CASES. 

TThen  newly  hatched  the  larva  is  pale  yellow,  with  the  head  and 
thoracic  plates  dark  brown  or  nearly  black.  The  full-grown  larva 
i  fig.  10.  c)  averages  5  mm.  to  5.3  mm.  in  length  and  1.16  mm.  in 
greatest  width.  Its  head  is  0.5  mm.  wide  and  is  dark  and  strongly 
chitinized.  with  the  ventral  surface 
lighter  than  the  rest.  The  body  is 
reddish  orange,  with  dark  plates  as 
follows:  The  cervical  plate  on  the 
prothorax.  subdivided  by  a  white 
interspace :  two  smaller  plates  on  the 
dorsum  of  the  mesothorax:  a  pair 
of  lateral  plates  on  each  thoracic  seg- 
ment :  a  large  anal  plate  on  the  termi- 

x  Tig.   0. — The   cases  of  the   cigar 

nal    segment;    a    Small    plate    On    the  hearer    (Coleophora   ftetchcrella .  :    a, 

side  of  each  anal  leg.     The  crochets        ^^r  Tiew  of  the  "gar-shaped  case, 

.        ~;  -11  showing   the   smooth   and   the  hairy 

On  the  fourth  pair  OI  abdominal  legs  sides  and  the  three-Iobed  hind  open- 

are   absent,    and    on   the   first   three        in^;  6'  side  view  of  s&me:  c>  the 

j.  .  case    as    it    appears    in    the    spring. 

pairs  are  rudimentary  or  wanting.  With  the  tubelike  addition;  d,  the 
varving  from  none  to  <L  in  one  or        fal1    and   winter   case-     Much   en' 

"       c  rr,  ii'i  /•  larged.     (Original.) 

two  rows.     I  he  anal  legs  have  from 

10  to  13  well-developed  crochets  placed  in  a  single  row.  The  spiracles 
are  round  and  feebly  indicated.  The  thoracic  legs  are  large,  dark 
brown,  strongly  chitinized.  and  with  a  chitinous  plate  behind  the 
basal  portion  of  each  leg.  The  seta?  on  the  head,  thoracic  legs,  and 
terminal  portion  of  the  body  are  distinct ;  on  the  abdominal  segments 
they  are  rather  indistinct.  The  abdominal  segments  are  distinctly 
divided  into  two  annulets,  and  the  dorsal  surface  of  each  annulet  is 
minutely  granular. 

The  case,  as  it  is  made  in  the  fall,  is  a  minute,  flattened  structure 
(fig.  9,  d)  composed  of  portions  of  the  upper  and  lower  skins  of  the 
leaf.  In  the  spring,  with  the  growth  of  the  larva?,  the  anterior  open- 
ing is  prolonged  into  a  tube  made  from  fragments  of  leaves  fastened 
by  silk  (fig.  9,  c).  The  second  case,  in  which  the  larva  finally  pu- 
pates (fig.  9.  a*  b).  is  longer,  cylindrical  or  cigar-shaped,  slightly 
compressed  laterally,  and  with  a  more  or  less  distinct  ridge  above  and 
beneath.  The  anterior  opening  is  round,  slightly  funnel-shaped,  and 
bent  downward,  so  that  the  plane  of  the  opening  forms  an  acute  angle 


38 


DECIDUOUS   FRUIT  INSECTS  AND   INSECTICIDES. 


with  the  longitudinal  axis  of  the  case.  The  posterior  end  terminates 
in  three  lobes,  which  neatly  close  the  opening.  The  average  length  of 
the  cigar-shaped  cases  is  G.5  mm.  and  the  width  1.3  mm.  They  are  of 
a  light  brownish  color,  much  like  that  of  the  dry  leaves.  As  the  case 
is  made  from  the  skin  of  the  upper  and  lower  sides  of  the  leaves,  the 
one  side  is  hairy  or  velvetlike,  while  the  opposite  side  is  almost 
smooth. 

THE    PUPA. 

The  pupa  (fig.  10,  h)  has  an  average  length  of  from  4  to  5  mm. 
It  is  light  brown,  long  and  slender,  terminating  posteriorly  in  a  broad, 
somewhat  depressed  cremaster,  with  two  short  lateral  spines  on  either 
side;  the  wing  sheaths  are  narrow,  with  free,  pointed  extremities 
reaching  almost  to  the  end  of  the  body;  the  hind  borders  of  the  ab- 
dominal segments  are 
smooth;  there  is  a 
chitinous  semiring- 
like ridge  on  the  an- 
terior portion  of  the 
third  to  seventh  ab- 
dominal segments. 
On  emergence  of  the 
adult,  the  pupal  skin 
remains  within  the 
case. 

THE  MOTH  OR  ADULT. 


Fig.  10. — The  cigar  case-bearer  (Coleophora  fletchcrclla)  : 
a,  Adult  female ;  6,  side  view  of  pupa  and  upper  view 
of  cremaster  of  same  ;  c,  larva  ;  d,  egg ;  e,  venation  of 
fore  and  hind  wings.     Much  enlarged.      (Original.) 


The  original  de- 
scription of  the  moth 
(fig.  10,  a,  e).  as  published  by  Fernald,a  is  herewith  given: 

Expanse  of  wings  from  10  to  12  mm.  Head,  palpi  and  basal  joint  of  the  an- 
tennae, yellowish  steel  gray.  Body,  legs  and  wings  above  and  beneath,  plain 
steel  gray,  much  more  intense  in  fresh  specimens.  The  palpi  are  without  tufts, 
the  basal  joint  of  the  antenna?  with  a  slight  tuft,  and  the  remaining  joints  of 
tho  antenna  and  also  the  joints  of  the  tarsi  are  steel  gray  annulated  with  white. 

The  two  sexes  are  similar  in  color,  the  male,  however,  being  smaller 
and  recognizable  by  the  blunt  termination  of  the  abdomen.  The 
abdomen  of  the  female  is  larger,  more  or  less  spindle-shaped,  and 
terminates  in  a  slender  ovipositor,  which  as  a  rule  protrudes  from 
the  last  segment.  The  wings  are  typically  like  those  of  the  Tineida?; 
narrow,  pointed,  with  the  veins  in  the  hind-wings  almost  obliterated; 
the  hind  border  of  both  wings  is  fringed  with  long  hairs,  which  are 
especially  pronounced  in  the  hind-wings.  On  emerging  from  the 
pupa  the  moth  as>umes  a  very  characteristic  pose,  as  illustrated  in 
Plate  II.  figure  1. 

a  Can.  Ent.,  1S92,  p.  122. 


Bull.  80,  Part  II,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  II. 


The  Cigar  Case-bearer. 

Fig.  1. — Apple  leaf  from  which  numerous  cases  have  been  constructed.  Fig.  2.— Overwintering 
larvse  (enlarged).  Fig.  3.— Apple  leaf  from  which  cigar-shaped  cases  have  been  made,  the 
empty  spring  cases  still  adhering  (enlarged).  Fig.  4. — Newly  emerged  moths  in  their  charac- 
teristic pose  on  the  empty  cases.     (Original.) 


THE   CIGAR   CASE-BEAKER.  39 

SEASONAL  HISTORY. 

In  the  early  spring,  as  the  buds  begin  to  open,  the  minute  larvae 
free  their  cases  (fig.  9,  d)  from  the  branches  where  they  have  over- 
wintered, and  begin  to  move  about  in  search  of  food.  Many  of  them 
reach  the  buds  before  these  are  opened,  and  eat  into  the  soft  inner 
tissues.  By  the  time  the  leaves  have  begun  to  expand  practically  all 
of  them  have  left  their  hibernating  places  and  are  actively  feeding 
upon  the  delicate  leaves. 

With  the  growth  of  the  larvae  an  addition  is  built  to  the  case  in  the 
form  of  a  tube.  This  extends  from  the  anterior  opening  on  the  lower 
side  of  the  case,  and  consists  of  fragments  of  leaves  and  silk.  (See 
fig.  9,  c.) 

Fletcher  observed  that  occasionally  a  larva,  on  reviving  in  the 
spring,  would  leave  its  old  case  and  make  a  new  one,  but  as  a  rule  the 
old  case  is  detached  from  its  winter  resting  place  and  is  used  for  some 
time  before  a  new  one  is  made. 

Toward  the  middle  of  May  the  larva  makes  a  case  of  an  entirely 
different  appearance.  After  having  undermined  a  sufficiently  large 
area  on  the  leaf,  the  larva  abandons  the  old  case,  which  usually  re- 
mains attached  to  the  leaf  (PI.  II,  fig.  3)  and.  from  the  upper  and 
lower  skins  of  the  leaf  cuts  out  the  future  case.  At  first  this  is  of  an 
elongated,  somewhat  flattened  shape,  but  as  it  becomes  lined  inside 
with  silk  it  assumes  a  more  cylindrical  or  cigar-shaped  form.  On 
close  observation  it  will  be  found  that  one  side  of  the  case  is  of  a 
hairy  or  woolly  structure,  while  the  opposite  side  is  smooth.  This  is 
readily  explained  by  the  fact  that  the  case  is  made  from  the  upper 
and  lower  epidermis  of  the  leaf,  the  lower  surface  being  hairy  and 
the  upper  practically  smooth.  In  this  case  the  larva  will  continue 
feeding  for  about  one  month.  During  that  period  it  grows  rapidly 
and  consumes  a  relatively  large  amount  of  food.  The  injury  caused 
at  this  time,  though  very  extensive,  is  perhaps  not  more  serious  than 
in  the  early  spring,  when  the  opening  buds  are  mutilated  or  killed 
by  young  larvae. 

For  some  unknown  reason  it  sometimes  happens  that  a  larva  with 
a  cigar-shaped  case  will  abandon  it  and  make  a  new  one  which  is 
apparently  similar  in  all  respects  to  the  one  previously  used.  The 
writer  has  also  observed  larvae  transforming  in  the  spring  cases. 
This  is  probably  owing  to  a  lack  of  food,  since  these  specimens,  as  a 
rule,  seldom  attained  their  full  size.  About  the  middle  of  June  the 
larvae  cease  feeding  and  migrate  from  the  leaves  to  the  branches. 
The  anterior  end  of  the  case  is  firmly  fastened  to  the  branch  by  means 
of  silk,  and  a  mass  of  silk  is  placed  in  the  same  end  for  the  attach- 
ment of  the  cremaster  of  the  future  pupa.  The  larva  turns  around 
within  the  case  before  transforming,  so  that  the  head  of  the  pupa  is 
30490°— Bull.  80—12 4 


40 


DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 


toward  the  posterior  and  free  end  of  the  case.  The  opening  at  this 
end  is  closed  by  three  lobes,  which  are  readily  pushed  apart  by  the 
emerging  adult.  A  day  or  two  after  the  fastening  of  the  case,  pupa- 
tion takes  place,  and  from  ten  to  twelve  days  later  the  adult  emerges. 
At  North  East,  Pa.,  the  first  adult  emerged  June  22 ;  the  maximum 
emergence  took  place  during  the  early  part  of  July,  while  after  July 
25  no  adults  emerged.  As  a  rule,  the  adults  emerge  in  the  afternoon, 
and  for  several  hours  remain  motionless  on  the  case  in  a  characteris- 
tic pose,  as  shown  in  figure  4  of  Plate  II.  Toward  evening  they 
become  restless  and  fly  off.  Moths  even  a  few  days  old  generally 
seek  their  favorite  resting  place  on  the  attached  cases. 

The  eggs  are  generally  laid  along  the  midrib,  on  the  underside  of 
the  leaves,  where  they  are  found  inserted  in  the  pubescence  or  down 
of  the  leaf.  A  few  eggs  were  similarly  found  on  the  hairy  branches. 
The  egg  period  lasts  from  fifteen  to  sixteen  days. 

The  newly  hatched  larvae  are 
quite  active,  and  were  found 
moving  about  for  several  hours 
before  eating  their  way  into  the 
leaves.  During  their  early  life 
they  are  true  miners  and  feed 
for  about  two  weeks  on  the  inner 
tissues  of  the  leaves.  Their 
mines  take  the  form  of  minute, 
elliptical,  brown  patches,  and 
are  readily  located  by  the  pres- 
ence of  the  black  powdery  ex- 
crement which  the  larvae  eject 
from  the  mines. 

Toward  the  beginning  of 
August  the  larvae  construct  a 
minute  case  from  the  upper  and 
lower  skins  of  the  mined  area  of  the  leaf.  Plate  II,  figure  1,  shows  a 
single  leaf  from  which  numerous  cases  of  this  kind  have  been  made. 
Before  the  foliage  is  ready  to  drop,  the  minute  case-bearers  migrate 
to  the  branches,  where  they  fasten  their  cases  and  seal  themselves  up 
for  the  winter.  During  the  latter  part  of  August  and  early  Sep- 
tember they  were  found  in  great  numbers,  especially  in  the  forks  and 
to  some  extent  on  the  lower  side  of  the  branches.  (See  PI.  II,  fig.  2.) 
For  seven  months  the  larvae  remain  thus  concealed  in  a  dormant  state, 
and,  as  previously  stated,  do  not  become  active  until  spring. 

A  general  idea  of  the  life  cycle  of  the  insert  may  be  obtained  from 
the  diagram,  figure  11.  It  shows  the  life  cycle  of  a  single  insect,  the 
dates  and  periods  shown  being  averages  for  the  insect  as  it  was  ob- 
served in  its  various  stages  in  the  field. 


Fig.  11. — Life  cycle  of  the  cigar  case-bearer  : 
Adapted  to  a  single  insect  under  average 
normal  conditons.      (Original.) 


THE  CIGAR   CASE-BEARER. 
ENEMIES. 


41 


PARASITES. 

Fletcher  in  1897  reported  a  hymenopterous  parasite  of  this  insect, 
Microdus  laticinctus  Ashm.,  from  Port  Hope,  Ontario. 

At  North  East,  Pa.,  at  the  time  of  the  emerging  of  the  adults, 
another  hymenopterous  parasite,  Habrocytus  sp.  (fig.  12),  as  deter- 
mined by  Mr.  J.  C  Crawford,  was  reared  in  considerable  numbers. 
About  10  per  cent  of  the  transforming  insects  were  parasitized. 

PREDACEOUS   ENEMIES. 

The  writer  found  that  the  eggs  of  the  case-bearer  were  extensively 
destroyed  by  a  minute  yellow  mite,  which  during  the  egg  period  was 
very  abundant  all 
over  the  orchard. 
The  larvae  of  the 
lacewing  fly 
(Chrysopa  oculata 
Say)  and  various 
species  of  ladybird 
beetles  vigorously 
attacked  the  eggs 
and  larva?.  ,    , 

*"* 

METHODS    OF 
CONTROL. 


-Habrocytus  sp.,  a  parasite  of  the  cigar  case-bearer. 
Greatly  enlarged.      (Original.) 


A  full  account 
of  the  results  of  FlG-  12- 
the  various  spray- 
ing experiments  carried  out  in  Canada  by  different  fruit  growers  will 
be  found  in  Fletcher's  report  for  1894  as  entomologist  and  botanist  for 
the  Canadian  experimental  farms,  pages  201  to  206.  It  was  well 
demonstrated  that  the  insect  can  be  held  under  control  with  either 
a  kerosene  emulsion  or  a  Paris  green  spray  applied  in  the  early  spring 
before  and  while  the  leaf  buds  are  opening. 

In  orchards  regularly  treated  with  arsenical  sprays  for  the  codling 
moth  the  cigar  case-bearer,  if  present  in  orchards,  will  undoubtedly 
be  kept  in  check. 


BIBLIOGRAPHY. 

1889.  Lintner,  J.  A.—Colcophora  sp.<5th  Rep.  Ins.  N.  Y.,  p.  324. 
1S90.  Lintner,  J.  A. — Coleophora  sp.    A  new  pear  insect.  <Proc.  Western  N.  Y. 
Hort.  Soc,  pp.  22-24. 

First  account  of  the  insect's  life  history ;  refers  to  injury  and  recom- 
mends an  arsenical  spray. 
Lintner,  J.  A. — Coleophora  sp.    A  new  pear  insect. < Popular  Gardening, 
Buffalo,  N.  Y.,  1890,  p.  198. 
Same  as  previous  account. 

1891.  Lintner,  J.  A. — Coleophora  sp.    A  new  pear  insect.<7th  Rep.  Ins.  N.  Y., 

pp.  347,  361. 

Same  as  above. 

1892.  Fernald,  C.  H. — Coleophora  fletcherella,  n.  sp.<Can.  Ent,  vol.  24,  pp. 

122-123. 

Original  description  of  the  species. 
Fletcher,  J. — Coleophora  sp.< Evidence  of  the  Entomologist  and  Botanist 
before  the  House  of  Commons,  p.  9. 

Brief  account  of  its  life  history  and  results  from  spraying. 
Fletcher,  J. — Coleophora  n.  sp.  The  cigar  case-bearer  of  the  apple. < Exp. 
Farms  [Canada],  Rep.  Ent  and  Bot.  for  1891,  pp.  196-198. 
Further  accounts  of  spraying  experiments. 

1893.  Fletcher,   J. — Coleophora   fletcherella    Fernald. < Exp.    Farms    [Canada], 

Rep.  Ent  and  Bot.  for  1892,  p.  4. 
Brief  mention. 
Lintner.  J.  A.— Coleophora  sp.  on  apple  leaves.<8th  Rep.  Ins.  N.  Y.  for 

1891,  pp.  264,  297. 
Lintner,  J.  A. — Coleophora  sp.<9th  Rep.  Ins.  X.  Y.,  p.  374. 
Brief  mention. 

1894.  Fletcher,  J.— -Coleophora  fletcherella   Fernald. <Evideneo  of  the  Ento- 

mologist and  Botanist  before  the  House  of  Commons,  p.  19. 
Brief  mention. 
Fletcher.  J. — Injurious  insects  of  the  year  1894.<25th  Ann.  Rep.  Ent. 
Soc.   Ont.,    pp.   79-SO. 

Short  account  of  the  life  of  C.  fletcherella  and  its  control. 
Fi.nciiER,  J. — The  cigar  case-bearer.<<  Jan.  Hort..  vol.  17,  p.  302. 
Inquiry  about  the  Cigar  case-bearer,  with  reply  by  Fletcher. 

L896.  Fletcher,  J. — Coleophora  fletcherella  Fernald.    The  cigar  case-bearer  of 

the  apple. < Exp.  Farms  [Canada  |,  Rep.  Ent  and  Bot.  for  1894.  pp. 

201-lmm;. 

Extensive  account  of  spraying  experiments. 
Bailey,  L.  II. — The  recent  apple  failures  of  western  New  York.<Cornell 

F.\p.   Bta.   Bull.  84. 
Si . i.m.i bland,  M.  V. — The  cigar  case-hearer. <Bull.  93,  Cornell  Agr.  Exp. 

Bta. 

An   rxh  ash.-  and  good  account  of  the  insect,   illustrated  with  photo- 
graphic reproductions. 

12 


THE  CIGAR  CASE-BEARER.  43 

1895.  Websteb,  F.  M.— Ohio  Farmer,  June  27.  1895,  p.  503,  3  figs. 

A  summarized  account  of  the  cigar  case-bearer  with  special  reference 
to  Cornell  Experiment  Station  Bulletin  93. 

1896.  Cockerell,  T.  D.  A. — Coleophora  fletcherella  Fernald.<Bull.  19,  N.  Mex. 

Agr.  Exp.  Sta.,  p.  117. 

Introduced  into  New  Mexico  on  infested  nursery  stock  from  New  York 
State. 
Fletcher,  J. — Insect  injuries  of  the  year  1895. < 26th  Ann.  Rep.  Ent.  Soc. 
Ont.,  p.  37. 

Mention  of  C.  fletcherella  Fernald. 
Fletcher,  J. — The  cigar  case-bearer  of  the  apple. <Can.  Ent,  vol.  28,  No. 
5,  pp.  128-130. 

A  brief  account  of  the  insect ;  reference  to  Slingerland's  work. 
Fletcher,  J. — The  cigar  case-bearer    (Coleophora  fletcherella  Fernald). 
<Exp.  Farms  [Canada],  Rep.  Ent.  and  Bot.  for  1895,  pp.  153-155. 
Further  spraying  experiments. 

1897.  Fletcher,    J. — The    cigar    case-bearer    (C.    fletcherella    Fernald). <Exp. 

Farms  [Canada],  Rep.  Ent.  and  Bot.  for  1896,  p.  252. 
A  brief  note  of  results  of  kerosene  emulsion  spray. 
Fletcher,  J. — Coleophora  fletcherella  Fernald. <27th  Ann.  Rep.  Ent.  Soc. 
Ont.,  p.  67. 

Parasite  :  Microdus  laticinctus  Ashm. 
Bethune,  C.  J.  S. — Notes  on  insects  of  the  year  1896. < 27th  Ann.  Rep. 
Ent.  Soc.  Ont.,  p.  57. 

Mention  of  C.  fletcherella  Fernald. 
Lowe,  V.  H. — Inspection  of  nurseries  and  treatment  of  infested  nursery 
stock. <Bull.  136,  N.  Y.  Agr.  Exp.  Sta.,  Geneva. 
Mention  of  C.  fletcherella  Fernald. 

1898.  Fayille,   E.   E.— The  cigar  case-bearer. < The  Industrialist,   April,   1898, 

pp.  271-275,  7  figs. 

An  account  of  its  occurrence  at  Manhattan,  Kans.,  life  history,  mode 
of  control. 

1899.  Beach,  S.  A.,  V.  H.  Lowe,  F.  C.  Stewart. — Common  diseases  and  injuri- 

ous insects  to  fruits. < Bull.  170,  N.  Y.  Agr.  Exp.  Sta.,  Geneva,  pp. 
381-445. 

Brief  description  of  C.  fletcherella  and  life  history. 

1900.  Forbes,  S.  A.— The  cigar  case-bearer. <21st  Rep.  State  Ent.  111.,  p.  146. 

Not  C.  fletcherella  Fernald,  as  reported. 
Felt,  E.  P. — Illustrated  descriptive  catalogue  of  some  of  the  more  in- 
jurious and  beneficial  insects.<Bull.  37,  N.  Y.  State  Mus.,  Vol.  VIII, 
pp.  8-9. 

Brief  note  on  C.  fletcherella  Fernald. 

1901.  Felt,   E.   P. — The  cigar  case-bearer. < Country   Gentleman,   November   7, 

p.  902. 

Brief  account  of  the  insect. 
Fletcher,  J. — Coleophora  fletcherella  Fernald. < Bull.  37,  Cent.  Exp.  Farm, 
Ottawa,  Can.,  p.  72. 

Brief  mention. 

1902.  Banks,    N. — Principal    insects    liable    to    be    distributed    on    nursery 

stock. < Bull.  34,  n.  s.,  Div.  Ent.,  U.  S.  Dept.  Agr.,  p.  38. 
Brief  mention. 

1903.  Lochhead,  W—  A  key  to  orchard  insects. <33d  Ann.  Rep.  Ent.  Soc.  Ont., 

pp.  104,  105,  108. 

Brief  mention  of  C.  fletcherella  Fernald. 


44  DECIDUOUS  FRUIT  INSECTS  AND   INSECTICIDES. 

1904.  Balk  will,  J.  A. — Report  on  insects  of  the  year.<34th  Ann.  Rep.  Ent. 
Soc.  Ont.,  p.  20. 

Brief  mention  of  C.  fletcherella  Fernald. 
Pettit,  R.  H. — Insects  injurious  to  fruits  in  Michigan. < Spec.  Bull.  27. 
Mich.  Agr.  Exp.  Sta. 

Brief  note  on  C.  fletcherella  Fernald. 


U.  S.  D.  A.,  B.  E.  Bui.  80,  Part  III.  D.  F.  I.  I.,  August  12, 1909. 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


ADDITIONAL  OBSERVATIONS   ON   THE  LESSER  APPLE 

WORM. 

(Enarmonia  prunivora  Walsh.) 

By  S.  W.  Foster  and  P.  R.  Jones, 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

INTRODUCTION. 

The  prevalence  of  the  lesser  apple  worm  throughout  the  apple- 
growing  districts  of  the  United  States  east  of  the  Rocky  Mountains, 
as  was  pointed  out  by  this  Bureau  in  1908,  has  awakened  considerable 
interest  among  apple  growers  and  others,  and  as  the  insect  has  become 
better  known  its  importance  as  a  pest  is  more  fully  realized.  Espe- 
cially noticeable  is  the  late  fall  injury  caused  by  the  later  broods,  some 
of  the  larvae  of  which  work  in  the  fruit  for  weeks  after  the  crop  is 
harvested. 

The  principal  purpose  of  the  present  paper  is  to  record  additional 
information  on  the  life  history  and  habits  a  of  the  insect,  and  to 
give  a  description  of  the  egg,  which  was  first  observed  during  the 
summer  of  1908,  both  at  Silo  am  Springs,  Ark.,  and  in  the  insect  ary 
of  the  Bureau  of  Entomology,  at  Washington,  D.  C. 

It  is  also  desirable  to  separate,  in  so  far  as  possible,  the  injurious 
work  of  the  lesser  apple  worm  from  that  of  a  larva  of  another  species 
which  closely  resembles  it,  and  which  latter  feeds  on  the  twigs  as  well 
as  the  fruit  at  certain  seasons  of  the  year. 

All  life-history  studies  were  made  under  normal  out-of-door  con- 
ditions. The  senior  author,  with  the  cooperation  of  Mr.  E.  L.  Jenne, 
made  the  observations  at  Siloam  Springs,  Ark.,  and  the  junior 
author,  who  also  furnished  the  description  and  photomicrograph 
of  the  egg,  conducted  the  observations  at  Washington. 

a  The  history,  distribution,  and  character  of  injury  of  this  species  have  been  fully 
given  by  Mr.  A.  L.  Quaintance  in  Bui.  68,  Part  V,  of  this  Bureau,  and  reference  to 
these  points  will  be  omitted  here. 

45 


46  DECIDUOUS   FRUIT  INSECTS  AND   INSECTICIDES. 

TWO   APPLE   CATERPILLARS   OTHER    THAN  THE   CODLING    MOTH. 

Early  in  the  season  of  1908  it  was  noticed  that  another  small  larva, 
the  adults  of  which  emerged  from  June  15  to  25,  resembling  very 
closely  that  of  Enarmonia  prunivora,  was  feeding  in  the  apples  and 
plums  around  Siloam  Springs,  Ark.  Later  in  the  season,  July  and 
August,  adults  were  reared  in  numbers  from  larvae  found  in  young 
vigorous  growing  shoots  and  water  sprouts  of  apple  trees.  Most  of 
the  injury  to  the  twigs,  however,  was  done  in  June  and  July. 

The  many  observations  by  the  writers  would  indicate  that  a  large 
part  of  the  first-brood  larvae  matures  in  the  fruit;  that  the  remainder 
of  the  first  brood  and  also  the  second  brood  mature  in  the  young 
twigs  and  water  sprouts;  and  that  the  larger  part  of  the  later  brood 
goes  back  again  to  the  fruit.  Adults  were  secured  from  fruit  from 
June  5  to  20.  After  June  23  no  more  specimens  were  reared  from 
fruit  until  August  17,  while  during  this  period  many  adults  were 
reared  from  the  twigs.  After  August  10  to  15  there  was  a  marked 
decrease  in  the  twig  injury  and  an  increase  in  fruit  infestation. 
Beginning  August  17,  many  adults  were  reared  from  apples  throughout 
the  remainder  of  the  season.  Adults  of  this  species  were  determined 
by  Mr.  August  Busck  as  Epinotia  pyricolana  Murtf.,  and  its  injuries 
to  fruit  have  not  apparently  been  heretofore  recorded.  This  species 
has  been  treated  by  Prof.  E.  D.  Sanderson  in  the  Twelfth  Report  of 
the  Delaware  College  Agricultural  Experiment  Station  (1900)  pages 
194-199. 

During  the  season  the  writers  were  unable  to  obtain  a  single  speci- 
men of  Enarmonia  prunivora  from  twigs  of  the  apple,  but  all  speci- 
mens taken  proved  to  belong  to  Epinotia  pyricolana.  In  the  Ozark 
region  and  also  in  the  vicinity  of  Washington,  D.  C,  this  species 
is  far  less  abundant  than  either  the  codling  moth  or  the  lesser  apple 
worm. 

COMPARATIVE  ABUNDANCE  OF  THE  LESSER  APPLE  WORM  AND 
THE  CODLING  MOTH  IN  APPLES. 

The  injury  caused  by  the  lesser  apple  worm  early  in  the  season  is 
not  so  pronounced,  nor  are  the  larvae  so  abundant  as  those  of  the 
codling  moth,  but  by  midsummer  and  fall  there  is  a  marked  increase 
in  the  number  of  larvae  of  this  species  over  that  of  the  codling  moth. 
This  increase  is  often  sufficient  to  bring  the  total  number  of  lesser 
apple  worms,  in  the  fruit  for  the  season,  in  excess  of  the  codling-moth 
larvae. 

Records  were  kept  of  the  comparative  abundance  of  the  two  species 
by  bringing  in  during  the  season  infested  fruit  from  unsprayed 
orchards  and  keeping  the  infested  fruit  collected  on  different  dates 
in  separate  breeding  cages.  Each  lot  was  examined  daily  for  full- 
grown  larvae  and  adults. 


THE   LESSER   APPLE   WORM. 


47 


Table  I  gives  the  relative  number  of  the  two  species  as  obtained 
from  wormy  apples  picked  from  the  trees,  each  picking  including 
some  windfalls,  which  would  tend  to  slightly  increase  the  percentage 
of  Enarmonia  larvae. 

Table  I. — Relative  seasonal  increase  of  Enarmonia  prunivora  over  codling  moth  larvae 
in  windfalls  and  in  fruit  picked  from  trees  in  orchard  of  D.  S.  Ballou,  Siloam  Springs, 
Ark.,  1908. 


Quantity  of  apples. 


Date  col- 
lected. 


|  Percent - 
Number   age  Enar- 
specimens     monia 
ofcodling  and  Epi- 
moth.         notia 
larvae.o 


1  gallon May  1 4 

\  gallon May  26 

2  gallons J  une    8 

2£  gallons June  30 

3  gallons July  16 

3  gallons j  Aug.    4 

4  gallons Aug.  22 


40 

30.5 
25.6 
40.5 

77.8 
59.3 

78.5 


a  Enarmonia  and  Epinotia  larvae  were  not  separated  in  Tables  I  and  II,  as  it  was  not  possible  to  readily 
distinguish  between  them.  However,  there  were  very  few  specimens  of  Epinotia  till  late  in  the  season, 
i.  e.,  after  the  middle  of  August,  and  then  in  small  numbers  as  compared  with  the  number  of  Enarmonia. 

Table  II,  prepared  by  Mr.  E.  L.  Jenne,  is  from  wormy  fruit  picked 
from  trees  at  intervals  stated,  no  windfalls  being  included. 

Table  II.— Relative  seasonal  increase  of  Enarmonia  prunivora  over  the  codling  moth 
in  fruit  picked  from  trees,  Flickenger  orchard,  Siloam  Springs,  Ark.,  1908. 


Number  of  apples. 

Date  col- 
lected. 

Number 
specimens 
Enar- 
monia 

and  Epi- 
notia. a 

Number 

specimens 

ofcodling 

moth. 

Percent- 
age Enar- 
monia 
and  Epi- 
notia 
larvae.o 

139 

May  26-7 
June  20 
June  30 
July  16 
July  31 
Aug.  16 
Sept.    1 

6 
10 
17 
17 
44 
95 
95 

80 
28 
22 
27 
77 
54 
39 

7.0 

56 

26  3 

58 

43  6 

64 

38.6 

156 

36.4 

129 

63.8 

107 

70.9 

a  See  footnote  to  Table  I. 

SEASONAL  HISTORY  AND  HABITS. 

Information  regarding  the  overwintering  or  hibernating  habits  of 
the  larva  of  this  insect  is  not  yet  complete.  Overwintering  larvae 
have  been  found  in  cracks  and  crevices  of  the  bark  of  trees,  and 
also  in  fruit  and  barrels  which  had  been  stored  over  winter.  Search- 
ing through  the  rubbish  around  the  apple  bin  of  a  vinegar  factory 
on  March  24,  Mr.  E.  L.  Jenne  and  the  writer  found  larvae  of  Enarmo- 
nia at  the  rate  of  4  to  135  larvae  and  pupae  of  the  codling  moth.  A 
few  days  later  234  larvae  and  pupae  of  the  codling  moth  located  from 
3  to  8  feet  above  ground  were  collected  from  the  framework  of  the  same 


48  DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 

apple  bin.  No  larvae  or  pupae  of  Enarmonia  were  found.  Larvae 
have  been  found  in  great  abundance  in  late  fall  in  the  partly  devoured 
fruit  of  Crataegus,  both  on  the  trees  and  on  the  ground.  Many  larvae 
passed  the  winter  in  this  fruit  in  our  breeding  jars,  and  this  overwin- 
tering habit  very  probably  obtains  under  natural  conditions.  (See 
PI.  Ill,  fig.  2.) 

From  many  observations  on  larvae  in  fruit  during  the  winter  months, 
the  difficulty  of  rearing  moths  in  spring  from  overwintering  material 
and  the  very  light  infestation  of  orchards  by  the  first-brood  larvae 
point  to  a  high  mortality  among  the  larvae  during  the  winter. 

Moths  from  overwintering  larvae  of  Enarmonia  emerge  about  the 
same  time  as  those  of  the  codling  moth.  At  Washington,  D.  C, 
moths  emerged  in  1908  from  April  26  to  28  and  during  the  first  few 
days  of  May  from  quantities  of  Crataegus  berries  which  had  been  kept 
out  of  doors  in  jars  and  cages  over  winter.  Mr.  Jenne  secured  adults 
April  18  to  30,  1909,  from  overwintering  larvae  at  Siloam  Springs, 
Ark.     Other  moths  emerged  May  1,  7,  and  9,  1909. 

At  Washington,  during  the  spring  of  1909,  moths  emerged  from 
the  fruit  of  Crataegus  maintained  under  out-of-door  conditions  as 
follows:   April  6,  1;  April  24,  3;  April  26,  6;  April  29,  3;  April  30,  4 
May  1,  6;  May  3,  6;  May  4,  9;  May  7,  14;  May  10,  29;  May  12,  9 
May  14,  7;  May  17,  1;  May  18,  3;  May  22,  2;  May  25,  3;  May  26,  1 
and  May  28,  1,  which  was  the  last  individual  to  appear. 

In  the  Ozark  region  the  first  brood  of  larvae  matures  usually 
during  the  month  of  June;  moths  for  the  second-brood  larvae  emerged 
in  1908  from  June  20  to  July  30.  Eggs  deposited  in  breeding  cages 
by  these  moths  July  10  to  12  produced  full-grown  larvae  July  30  to 
August  10,  the  adults  emerging  August  14  to  26.  Eggs  from  these 
latter  gave  another  brood  of  full-grown  larvae  September  19  to  30. 
Other  adults,  emerging  later,  deposited  eggs  as  late  as  September  7 
to  14,  the  full-grown  larvae  leaving  the  fruit  October  3  to  November 
6,  when  observations  ceased,  some  larvae  being  still  at  work  in  fruit.a 
This  is  strong  evidence  of  three  full  generations  annually  for  the  Ozark 
region.  Since  many  moths  had  emerged  from  first-brood  larvae 
before  July  10  to  12,  when  the  above  individual  records  began,  it 
is  possible  that  some  of  the  earlier  ones  emerged  in  time  to  give  rise 
to  a  partial  fourth  brood  of  larvae. 

LIFE  CYCLE  AND  DURATION  OF  STAGES. 
THE   EGG. 

Individual  records  kept  for  120  eggs  during  July,  August,  and  Sep- 
tember gave  the  minimum  time  of  incubation  as  four  and  one-sixth 
davs  and  the  maximum  five  and  one-half  days.     Most  of  the  eggs 

"  Moths  emerged  as  late  as  September  26,  but  no  records  were  kept  of  eggs  deposited 
after  September  14. 


Part         E     eai     :  Entomology,  U.  S.  Dept.  of  Ag'ico  hire  PLATE   IN. 


Fig.  1.— Photomicrograph  of  Egg  of  Lesser  Apple  Worm  <Enarmonia 
prunivora  .     'Original. 


Fig.  2.— Work  of  Lesser  Apple  Worm  on  Fruit  of  Crataegus.    Twice 
Enlarged.    (Original) 


THE   LESSER  APPLE   WORM. 


49 


hatched  between  one  hundred  and  six  and  one  hundred  and  twenty- 
four  hours  after  deposition,  the  average  being  slightly  more  than  five 
days. 

The  following  table  of  group  records  taken  from  batches  of  eggs 
deposited  on  sides  of  breeding  cages  and  on  apple  foliage  kept  inside 
of  cages  shows  the  approximate  time  of  incubation: 

Table  III. — Period  of  incubation  of  eggs  of  Enarmonia  prunivora  under  normal  out- 
of-door  conditions,  Siloam  Springs,  Ark.,  1908. 


Num-     Date  de- 
ber  of    posited, 
eggs,    i  night  of— 

Black  spot  appeared. 

Egg  hatched. 

Time. 

7 

Aug.  28 
Aug.  29 
Sept.    6 
Sept.    7 
Sept.    9 
Sept.  11 
Sept.  12 

Sept.  13 
Sept.  14 

September  3,  a.  m 

Days. 
5 

3 

September  4,  a.  m 

September  12,  a.  m 

1 

5J 

5 

September  13,  a.  m 

b| 

11 

September  15,  a.  m 

5J 
5i 

11 

September  16,  a.  m 

September  16,  p.  m 

35 

September  17,  a.  m 

September  17,  p.  m 

4§-5i 

4 

September  18,  p.  m 

September  19,  a.  m 

September  19,  a.  m 

4J-5J 

5J 

6 

September  19,  p.  m 

September  20,  a.  m 

51 

THE    LARVA. 

The  length  of  the  larval  period  from  time  of  hatching  to  leaving 
fruit  varied  from  thirteen  to  fifteen  days  during  July,  from  twenty 
to  twenty-seven  days  in  August  and  the  first  half  of  September, 
and  increased  to  from  thirty  to  fifty  days  after  the  middle  of  Sep- 
tember to  early  November. 

Individual  records  for  over  100  larvae  show  a  minimum  of  thirteen 
days  and  a  maximum  of  fifty  days  for  actual  time  in  fruit  of  normal 
healthy  larvae  which  left  fruit  prior  to  November  6. 


THE  LARVA  IX  COCOOX  BEFORE  PUPATING. 

This  period  varies  greatly,  according  to  where  the  larva  is  kept, 
being  much  longer  when  confined  with  bits  of  paper,  etc.,  in  glasses. 
From  about  100  specimens  allowed  to  spin  cocoons  in  ends  of  apples, 
either  at  the  stem  or  blossom  end,  the  average  time  during  the  months 
of  July  and  August  was  seven  to  eight  days  from  leaving  the  fruit 
to  pupation,  the  minimum  being  one  day  and  the  maximum  twelve 
days. 

THE   PUPA. 

The  actual  duration  of  the  pupal  stage  varies  from  a  minimum  of 
four  (?)  to  a  maximum  of  seventeen  days,  averaging  about  ten  days. 
Seventy-four  per  cent  of  all  pupae  observed  in  Arkansas  developed 
moths  in  between  eight  and  twelve  days.  The  records  in  Washington 
agree  very  closely  with  those  in  Arkansas. 


50  DECIDUOUS  FRUIT  INSECTS   AND  INSECTICIDES. 

The  total  time  in  the  cocoon,  from  the  date  of  full-grown  larvae 
leaving  the  fruit  to  the  emergence  of  the  moths,  varies  from  thirteen 
to  thirty  days,  although  normally  it  is  about  seventeen  days.  Seventy 
per  cent  of  all  moths  emerged  between  thirteen  and  eighteen  days 
after  the  larvae  left  the  fruit. 

Taking  the  normal  or  average  figures  for  each  stage,  the  complete 
life  cycle  requires  approximately  six  weeks,  but  many  individuals 
complete  the  life  cycle  in  thirty  days  in  early  summer.  During  the 
period  from  August  to  October  some  individuals  required  as  high 
as  forty  to  fifty  and  a  few  to  sixty  days. 

DESCRIPTION  OF  EGG." 

Egg:  Size,  0.53  to  0.70  mm.  long  by  0.51  to  0.55  mm.  wide;  oval 
in  outline,  varying  to  roundish,  slightly  convex,  and  covered  with  a 
network  of  irregular  ridges.  At  time  of  deposition  it  is  pearly  white, 
and  resembles  very  closely  in  general  appearance  the  egg  of  the 
codling  moth,  except  for  its  smaller  size,  the  ridges  being  somewhat 
closer  together  and  not  so  prominent  as  with  the  latter.     (See  PI.  Ill, 

%  i.) 

The  eggs  assume  a  yellowish  cast  one  or  two  days  after  deposition, 
shortly  after  which  a  red  ring  appears;  the  black  head  of  the  larva 
usually  appears  in  four  days. 

Moths  confined  in  rearing  cages  deposited  eggs  on  both  sides  of 
the  leaves,  but  mostly  on  the  upper  surface  on  the  fruit,  stems,  and 
on  the  glass  door  and  wooden  uprights  of  the  rearing  cage. 

PARASITES. 

Only  one  parasite  is  recorded  in  literature  from  this  species,  viz, 
Mirax  grapholithse  Ashm.  During  the  past  season  a  specimen  was 
reared  from  a  larva  infesting  apple,  which  has  been  determined  by 
Mr.  H.  L.  Viereck  as  PJianerotoma,  n.  sp. 

CONTROL  MEASURES. 

The  usual  treatment  practiced  against  the  codling  moth  has  so 
far  served  to  very  effectively  keep  in  check  serious  injury  by  this 
species. 

a  Since  this  paper  was  submitted  for  publication  the  egg  stage  has  been  -well 
described  by  E.  P.  Taylor  in  Journ.  Econ.  Ent.,  June,  1909,  p.  237. 


U.  S.  D.  A.,  B.  E.  Bui.  80,  Part  IV.  D.  F.  I.  I.,  September  1,  1909. 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


THE  PEAR  THRIPS  AND  ITS  CONTROL." 

(Euthrips  pyri  Daniel.) 

By  Dudley  Moulton, 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

INTRODUCTION. 

Cultivation  and  spraying,  the  principal  treatments  involved  in  the 
control  of  the  pear  thrips,  are  largely  subject  to  suitable  weather  con- 
ditions, and  each,  to  be  effective,  must  be  accomplished  at  its  proper 
time.  Other  orchard  work,  such  as  irrigation,  cultivation,  pruning, 
and  spraying  for  other  insect  and  fungous  troubles,  must  therefore  be 
considered  well  beforehand  and  completed  or  so  arranged  that  nothing 
will  interfere  with  the  treatment  for  the  thrips.  It  is  highly  impor- 
tant that  the  individual  orchardist  should  have  everything  in  readiness 
to  treat  his  own  orchard  at  exactly  the  right  time.  Preparedness  for 
and  thoroughness  in  the  work  of  spraying  and  in  plowing,  it  will  be 
found,  are  the  most  important  factors  in  the  successful  control  of  this 

msect 

DISTRIBUTION. 

The  pear  thrips  is  known  to  occur  only  in  the  central  part  of  Cali- 
fornia, and  especially  in  localities  in  the  general  neighborhood  of  the 
San  Francisco  Bay.  Reports  of  its  ravages  have  been  received  from 
the  Sierra  Nevada  foothills,  near  Newcastle  and  Auburn,  and  from  the 

a  The  control  of  the  pear  thrips  has  been  for  several  years  the  principal  problem 
confronting  the  growers  of  deciduous  fruits  in  portions  of  central  California.  This 
insect,  on  account  of  its  mode  of  attack  and  habits,  has  presented  unusual  difficulties 
in  control.  It  is  believed,  however,  that  the  investigations  of  the  Bureau  of  Ento- 
mology have  now  determined  practical  and  efficient  measures  which,  if  carefully 
followed  out  by  orchardists,  will  insure  its  reduction  below  injurious  numbers.  The 
investigation  has  involved  a  large  amount  of  detailed  study  of  the  insects'  behavior 
on  the  trees  and  in  the  ground,  and  the  testing  of  a  large  series  of  spray  mixtures,  fer- 
tilizers, soil  fumigants,  etc.  Mr.  Moulton  has  been  continuously  engaged  in  the  work 
for  the  past  three  years,  assisted  a  part  of  the  time  by  Messrs.  Charles  T.  Paine  and  P.  R. 
Jones.  Beginning  with  the  spring  of  1909,  Mr.  S.  W.  Foster  was  charged  with  the 
operations  in  Contra  Costa  County  and  northward,  Mr.  Fred  Johnson  collaborating  dur- 
ing the  spring  months.  The  present  is  the  second  report  upon  the  pear  thrips,  the  first, 
published  as  Part  I  of  Bulletin  68  of  this  Bureau,  dealing  largely  with  the  insect's  life 
history  and  habits. — A.  L.  Quaintance. 

51 


52  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 

Tulare  and  Fresno  fruit  districts,  but  it  was  found  after  a  careful 
investigation  that  none  of  these  fruit  areas  was  infested.  In  the  one 
case,  at  Newcastle,  the  injury  was  evidently  that  of  the  blossom  pear- 
blight  and  not  a  single  pear  thrips  could  be  found  in  the  whole  region 
at  a  time  when  the  insects  should  have  been  in  evidence  in  greatest 
numbers.  A  few  thrips  of  another  species  (Euthrips  occidentalis 
Pergande)  were  found  in  pear  and  cherry  blossoms  in  this  locality,  but 
this  insect  is  not  injurious  to  fruits,  and  its  presence  in  blossoms  is  of 
no  consequence.  Thrips  from  pear  blossoms  at  Visalia  were  found  to 
be  of  the  species  Euthrips  tritid  Fitch,  which  also  is  not  usually  injuri- 
ous to  fruit  trees.  The  present  infestation,  then,  is  confined  to  the 
region  around  and  closely  adjoining  the  San  Francisco  Bay.  It 
extends  south  through  the  Santa  Clara  Valley  and  into  Hollister,  San 
Benito  County,  north  through  Alameda,  Contra  Costa,  Solano,  and 
Yolo  counties,  and  also  occurs  in  some  rather  small  areas  along  the 
Sacramento  River.  The  area  of  deciduous  fruits,  about  60,000  acres, 
in  the  Santa  Clara  Valley,  is  practically  all  more  or  less  infested  by  the 
thrips;  and  the  other  infested  orchard  sections,  such  as  Hollister, 
Walnut  Creek,  and  Concord,  in  Contra  Costa  County,  and  Suisun  and 
Vaca  orchards  and  others  along  the  Sacramento  River,  also  include 
many  hundreds  of  acres. 

The  original  home  of  this  species  is  still  in  doubt.  Several  men 
have  expressed  the  opinion  that  it  is  of  European  origin,  but,  accord- 
ing to  Doctor  BufTa,  the  insect  does  not  occur  in  Europe,  and  after 
examining  the  species  he  believes  it  to  be  of  eastern  origin,  suggesting 
China  as  possibly  its  original  home. 

The  various  thrips  which  are  seen  in  roses  and  in  other  flowers,  and 
which  can  be  found  at  almost  any  time  of  the  year,  should  not  be 
mistaken  for  the  pear  thrips,  which  is  distinctly  a  fruit-tree  pest  and 
does  not  attack  grass,  weeds,  or  cultivated  flowers.  It  has,  once  or 
twice,  been  collected  from  leaf  clusters  of  rose  bushes,  but  this  is  not 
common.  The  name  "pear  thrips"  was  given  because  the  insect  was 
first  found  in  pear  blossoms,  but  this  does  not  indicate  that  it  attacks 
pear  trees  only.  The  injury  on  prunes  and  other  fruit  trees  is  equally 
as  serious  as  that  on  pears.  Thrips  should  not  be  confounded  with  the 
vine  hopper  Typlilocyba  comes  Say,  an  insect  which  is  wrongly  called 
u  thrips, M  but  is  not  a  thrips  at  all.  The  term  "  thrip,"  so  commonly 
used,  is  also  erroneous,  as  the  word  "thrips"  is  both  singular  and 
plural. 

CHARACTER  OF  INJURY. 
FEEDING    INJURY    BY    ADULTS. 

Adult  thrips  appear  on  trees  during  late  February  and  early 
March,  when  the  buds  are  just  beginning  to  open  (PI.  IV).  They 
remain  on  the  tree  until  late  in  April  and  are  thus  feeding  all  through 


THE  PEAR  THRIPS  AND  ITS   CONTROL.  53 

the  period  of  the  early  opening  of  buds,  of  blossoming,  and  of  the 
unfolding  of  leaves  and  the  setting  of  fruit.  They  come  to  the  trees 
ravenously  hungry  after  a  long  fast  of  ten  or  eleven  months  in  the 
ground,  and  they  force  an  entrance  as  soon  as  possible  into  the  first 
opening  buds.  Their  habit  of  getting  inside  immediately  has  led 
many  orchardists  to  believe  that  they  in  some  mysterious  way  gain 
entrance  into  the  buds  before  these  are  opened.  This  is  not  the  case, 
as  the  insects  never  enter  until  after  the  buds  are  swollen  and  partly 
or  wholly  opened  at  the  tips.  They  do  not  feed  on  the  tough  tissues 
of  the  bark  or  on  the  outer  bud  scales,  but  wait  until  they  can  get 
inside.  When  thrips  are  very  numerous  these  early  buds  either 
never  open  at  all  or  form  only  weak  blossoms,  which  present  the 
appearance  of  having  been  burned  (PI.  V,  fig.  1).  Thrips  will  usually 
migrate  in  search  of  new  food  plants  after  the  blossoms  are  thus  com- 
pletely destroyed,  which  explains,  in  part  at  least,  why  they  may 
temporarily  disappear  from  a  given  orchard  or  part  of  an  orchard, 
where  perhaps  a  few  days  previous  they  had  been  numerous  enough 
to  destroy  the  entire  crop.  When  thrips  are  less  numerous  the 
injury  is  accumulative,  but  it  may  finally  prove  as  serious  as  when 
many  more  thrips  are  present.  A  few  individuals  may  continue  to 
feed  within  clusters  for  days  or  even  weeks.  The  growth  of  the  tree 
is  then  retarded  and  its  blossoms  and  leaves  become  weak  and  de- 
formed. Trees  may  produce  a  heavy  bloom,  even  where  many  thrips 
are  present,  but  the  blossoms  and  leaf  stems  will  be  scarred,  weak- 
ened, and  abnormally  short  and  the  fruit  does  not  set.  This  is 
especially  true  of  prunes.  A  few  adult  individuals  may  feed  in  a 
cluster  of  pear  blossoms,  and  although  the  buds  drip  with  exuding 
sap  and  are  moldy,  many  if  not  all  of  these  pears  may  set  and  there 
may  follow  a  heavy  crop  of  fruit,  but  always  in  such  cases  the  fruit 
is  ill  shaped  and  badly  scabbed.  The  scabbing  on  pears  (PL  V)  is 
accomplished  almost  entirely  by  adults  which  feed  within  the  clusters 
of  buds,  while  scabbing  of  prunes  (PL  VI)  is  done  almost  entirely  by 
larvse  which  feed  on  the  fruits  under  protection  of  the  old  calices 
before  these  are  sloughed  off. 

Injury  by  adults  in  almonds,  apricots,  and  peaches  is  not  serious 
unless  very  many  individuals  are  present.  These  trees  bloom  rather 
early,  and  since  each  blossom  comes  singly  in  a  bud,  there  is  offered 
almost  no  opportunity  for  the  thrips  to  get  inside  until  the  blossom 
itself  is  well  opened,  whereupon  the  thrips  feed  mostly  on  the  nectar 
glands  inside  the  calyx.  This  part  of  the  blossom  can  accommodate 
quite  a  few  thrips  without  receiving  serious  injury,  and  also  the  insect 
is  diverted  from  feeding  on  the  more  vital  parts.  There  follows 
serious  injury  on  these  fruits  only  when  many  waiting  individuals 
enter  the  buds  and  feed  on  the  outside  of  the  little  calyx  cups  and  the 


Bui.  80,  Pan  IV,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  V. 


Fig.  1.— Destruction  of  Buds  and  Blossoms.    (Original. 


Fig.  2.— Scabbing  of  Fruit  from  Feeding  Punctures  by  Adults  on  the  Opening 
Buds  in  Spring.    (Original.) 

WORK  OF  PEAR   THRIPS  ON    PEAR. 


Bui.  80,  Part  IV,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  VI. 


Work  of  the  Pear  Thrips  on  French  Prune. 

Fig.  1.— Shoot  on  which  crop  has  been  largely  destroyed  in  blossom  stage.  Fig.  2.— Young  fruit, 
natural  size,  showing  scabbing  resulting  from  work  of  larvae.  Fig.  3.— Mature  fruit  showing 
scabbing  injury,  resulting  in  a  low  grade  of  dried  fruit.     (Original.) 


THE   PEAK   THEIPS   AND   ITS   CONTROL.  55 

The  period  of  blossoming  for  similar  varieties  in  Contra  Costa 
County  is  about  the  same  as  that  in  the  Santa  Clara  Valley,  while  the 
orchards  in  the  Vaca  and  Suisun  valleys  and  along  the  Sacramento 
River  may  be  a  very  few  days  earlier. 

INJURY   TO    TREES    BY    OVIPOSITION. 

The  adult  female  is  equipped  with  a  pointed  and  curved,  sawlike 
ovipositor  (fig.  13),  by  means  of  which  deep  cuts  are  made,  into  which 
the  eggs  are  placed  well  down  into  the  tissues  of  the  plants,  mostly 
in  the  stems  of  blossoms  or  leaves  or  into  the  leaf  tissue.  A  single 
incision  is  minute  and  in  itself  does  little  harm,  as  the  wound  soon 
heals  over,  but  the  tiny  stems  of  the  blossoms  or  of  newly  setting 
fruits  and  the  leaf  petioles  are  unfortunately  preferred  by  the  insect 
for  ovipositing  situations,  so  that  many  incisions  are  often  cut  into  a 
single  stem,  which,  becoming  greatly 
weakened,  turns  yellow  and  the  fruit 
falls.  This  injury  becomes  very  notice- 
able at  times  on  the  prune  and  cherry 
and  is  undoubtedly  the  cause  of  much 
dropping  of  immature  fruit. 

INJURY   BY   LARVAE. 

Thrips  larvae  are  wingless,  never  of 
their  own  accord  traveling  from  the 

-,        ,      -.       ,  i  •   i    j_i  -i  j  Fig.  13.— The    pear   thrips    (Euthrips 

host  plant  on  which  they  are  bom,  and    pyri):  ovipositor  and  end  of  abdomen 

Usually  do  not  move  far   from    the   im-      from  side.    Much  enlarged.  (Author's  illus- 

mediate  locality  where  they  have  issued 

from  the  egg.  They  seek  some  sheltered  place  within  a  cluster  of 
leaves,  in  blossoms,  or  under  the  protection  of  the  drying  calices  of 
such  fruits  as  prunes  or  cherries.  Larvae  are  found  mostly  during  the 
last  of  March  and  in  April  and  their  injury  is  distinctly  on  leaves  and 
fruits  and  not  in  opening  buds.  To  them  must  be  attributed  almost 
all  the  scabbing  on  prunes  (PL  VI,  figs.  2,  3),  some  silvering  on  apri- 
cots and  peaches,  and  most  of  the  deformed,  ragged,  and  partly  dead 
leaves.  This  injury  to  the  foliage  greatly  stunts  and  weakens  a  tree 
if  it  is  repeated  during  several  successive  years. 

SEASONAL  HISTORY  AND  HABITS. 
APPEARANCE   OF   ADULTS    FROM    SOIL   IN    SPRING. 

The  following  table  shows  clearly  just  when  the  first  adult  thrips 
are  leaving  the  ground,  when  in  maximum  numbers,  and  when  the 
last  individuals  are  appearing.  The  figures  here  represent  the  total 
number  of  thrips  collected  from  four  cages  from  each  of  four  orchards 

30490°— Bull.  80—12 5 


56 


DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


in  the  Santa  Clara  Valley,  namely,  the  Landon,  Bogen,  Sorosis,  and 
Hume  orchards.  The  cages  each  contained  a  solid  block  of  earth 
17  by  17  inches  square,  representing  a  surface  area  of  2  square  feet 
and  a  depth  of  18  inches,  below  which  thrips  have  never  been  found. 
These  cages  were  removed  from  under  prune  and  pear  trees  in  the 
several  orchards,  brought  to  the  laboratory  yard,  and  again  em- 
bedded in  the  ground  to  their  usual  depth  and  covered  with  a  special 
cage.  A  daily  record  was  made  of  the  thrips  issuing  from  each 
case. 


Table  I. — Records  of  emergence  from  soil  of  adult  pear  thrips  from  four  orchards  in  the 
Santa  Clara  Valley,  California,  spring  of  1909 . 


Number  of  thrips  in  four  cages. 

Total.  ; 

Date. 

Number  of  thrips  in  four 

cages. 

Date. 

From 

From 

From 

From 

From 

From 

From 

From 

Total. 

Lan- 

Bogen 

Sorosis 

Hume 

| 

Lan- 

Bogen 

Sorosis 

Hume 

don  or- 

or- 

or- 

or- 

don or- 

or- 

or- 

or- 

chard. 

chard. 

chard. 

chard. 

chard. 

chard. 

chard. 

chard. 

1909. 

1909. 

Feb.  15 

18 

0 

0 

0 

18 

Mar.  11 

13 

47 

128 

310 

498 

16 

0 

0 

0 

0 

0 

12 

12 

62 

81 

183 

338 

17 

51 

0 

0 

1 

52 

13 

18 

101 

87 

207 

313 

18 

176 

8 

4 

4 

192 

14 

1 

53 

70 

124 

248 

19 

160 

14 

4 

14 

192 

15 

3 

71 

76 

129 

279 

20 

126 

17 

12 

14 

169 

16 

1 

59 

74 

125 

259 

21 

60 

1 

0 

14 

75 

17 

3 

31 

36 

72 

152 

22 

84 

10 

7 

18 

119 

18 

1 

15 

13 

13 

42 

23 

106 

5 

7 

17 

135 

19 

8 

12 

22 

19 

61 

24 

403 

26 

50 

73 

552 

20 

1 

6 

3 

18 

28 

25 

301 

35 

49 

74 

459 

21 

0 

1 

1 

0 

2 

26 

320 

25 

35 

64 

444 

22 

2 

0 

2 

2 

6 

27 

232 

19 

28 

134 

414 

23 

0 

3 

3 

7 

13 

28 

372 

74 

80 

255 

781 

24 

0 

0 

0 

3 

3 

Mar.    1 

340 

109 

114 

218 

781 

25 

0 

0 

0 

2 

2 

2 

104 

54 

92 

285 

535 

26 

1 

0 

1 

1 

3 

3 

300 

188 

258 

553 

1,299 

27 

0 

0 

4 

3 

7 

4 

191 

104 

115 

304 

714 

28 

0 

0 

0 

7 

7 

5 

37 

93 

109 

269 

508 

29 

0 

0 

0 

0 

0 

6 

26 

34 

87 

215 

362 

30 

1 

1 

0 

0 

2 

7 

13 

50 

60 

315 

438 

31 

0 

0 

0 

0 

0 

8 

9 

38 

14 

158 

219 

Apr.     1 

0 

0 

0 

3 

3 

9 

18 

89 

77 

602 

776 

2 

0 

0 

0 

0 

0 

10 

18 

114 

109 

256 

497 

3 

0 

0 

1 

0 

1 

The  first  adult  thrips  were  collected  on  February  15,  but  a  very 
few  individuals  had  been  found  in  blossoms  previous  to  this  time. 
On  February  18  they  were  numerous  in  one  of  our  experiment 
orchards,  and  by  February  25  they  were  common  in  all  orchards. 
Maximum  emergence  begins  about  February  19  and  continues  until 
about  March  16,  a  period  of  three  and  one-half  weeks.  A  few  strag- 
gling individuals  continued  to  come  out  during  all  the  latter  part  of 
March  and  a  very  few  even  in  April.  Practically  all  thrips,  however, 
are  out  of  the  ground  by  March  20. 

The  emergence  period  for  thrips  in  orchards  in  Contra  Costa  and 
Solano  counties  seems  to  be  three  or  four  days  earlier  and  this  will 
probably  hold  true  also  for  orchards  along  the  Sacramento  River. 


THE  PEAK  THKIPS  AND   ITS   CONTROL.  57 

MIGRATION  OF  ADULTS. 

The  migration  of  adult  thrips  is  as  yet  only  imperfectly  understood. 
They  have  wings  and  are  free  to  fly  if  they  choose,  but  weather  condi- 
tions and  food  supply  influence  very  decidedly  their  inclination  to  move 
about.  The  tendency  is  for  the  thrips  to  remain  quite  closely  with 
the  trees  wherever  there  are  only  a  few  individuals  and  where  the 
supply  of  food  is  abundant.  They  then  fly  up  during  the  warm, 
quiet  parts  of  the  day,  but  do  not  travel  far.  It  often  happens  that 
the  insects  are  so  numerous  as  to  kill  the  early  buds  or  to  so  injure 
them  that  these  become  brown  and  dried  and  do  not  offer  suitable 
food;  the  thrips  then  migrate  to  other  less  affected  orchards.  This 
migration  often  occurs  before  the  period  of  oviposition  begins,  in 
which  case  no  new  brood  is  started  to  infest  such  an  orchard  during 
the  following  year.  This  explains  why  thrips  may  injure  an  orchard 
during  one  season  and  seem  to  have  almost  entirely  disappeared  from 
it  the  next .  This  occurrence  has  le d  some  orchar d- 
ists  to  believe  that  eventually  the  thrips  may  move 
away  permanently  or  die  out.  This  supposition  is 
not  correct,  and  it  will  be  only  a  matter  of  a  year 
or  two  until  these  orchards  will  again  be  attacked. 

Migration,  then,  occurs  only  during  warm,  clear 
weather  and   is  hastened  by  a  desire  for  better 

£       i  <>  -x    -li  t/-  <•  •  Fig.  14.— The  pear  thrips: 

food  or  tor  suitable   conditions  tor  ovipositing.       Eggs.  Highly  magni- 
Thrips  locally  do  not    travel  in    any  particular       fied-  (Author's  mustra. 
direction,  such   as   south,   or  east,   or  west,  but 
distribute  themselves  generally  wherever  conditions  Are  favorable  for 
their  propagation. 

OVIPOSITION. 

During  the  season  of  1909  oviposition  was  not  observed  until 
March  10,  and  by  March  15  any  number  of  individuals  could  be  seen 
placing  their  eggs.  A  few  larvae,  however,  were  collected  from  almond 
trees  on  February  26,  indicating  that  earlier  eggs  had  been  placed. 
The  period  of  maximum  oviposition  begins  about  March  15,  and 
almost  all  individuals  will  be  found  placing  eggs  after  this  date  for 
a  period  of  about  four  weeks.  Ovipositing  continues  early  and  late 
during  the  day  and  in  all  conditions  of  weather. 

THE  EGG. 

The  egg  (fig.  14),  a  white,  bean-shaped  body,  is  always  embedded 
in  the  tender  tissue  of  the  stem,  leaf,  or  in  small  fruits,  and  is  thus 
protected.  After  about  four  days  the  larva  hatches  and  pushes  out 
through  the  incision  immediately  above  it. 


58 


DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 


THE   LARVA. 


The  thrips  larva  (fig.  15)  is  white,  with  red  eyes;  it  moves  about 
slowly  and  does  not  jump,  and,  being  without  wings,  it  can  not  fly. 
It  does  not  spin  a  web,  but  seeks  a  sheltered  place  between  rolled  or 
folded  leaves  or  in  blossoms,  or  it  lies  close  along  the  veins  on  some 
of  the  Larger  leaves.  It  reaches  full  growth  after  two  or  three  weeks, 
drops  to  the  ground,  and  penetrates  into  it  for  several  inches,  where 
it  incloses  itself  in  a  tiny  cell  and  here  remains  during  all  the  rest  of 
the  year. 

Larvae  do  not  walk  down  the  larger  branches  or  tree  trunks  to  get 
to  the  ground,  but  drop  down  or  are  carried 
within  the  old  falling  calices,  or  are  more 
usually  thrown  down  by  winds  or  rains.  It 
has  been  observed  that  a  very  large  percent- 
age of  the  thrips  which  are  thus  thrown  from 
the  tree  are  not  fully  grown.  Only  those 
which  are  mature  are  able  to  penetrate  the 
ground  and  form  their  cells;  the  others  die. 
yS  -^v       Larvae   are   scattered   everywhere  under  the 

>  ^    trees,  and  if  the  trees  are  large  and  have  inter- 
_^'  mingling  branches  the  thrips  are  distributed 

over  nearly  the  whole  surface  of  the  soil. 

The  period  during  which  larvae  are  entering 
the  ground  begins  about  April  1,  and  is  at  its 
maximum  from  about  April  10  to  30,  practi- 
cally all  thrips  having  entered  by  May  15. 
This  period  of  entering  the  ground  by  larvae 
in  Contra  Costa  County  corresponds  very 
closely  to  the  San  Jose  record  as  given  above. 
It  may  be  a  few  days  earlier  in  the  warmer 
sections  at  Suisun,  in  the  Vaca  Valley,  and 
along  the  Sacramento  River. 

Larvae  penetrate  the  loose  top  soil  and 
usually  remain  in  the  3  or  4  inches  of  harder 
below  the  surface.  They  penetrate  to  a 
where  the  soil  is  loose,  owing  to  shallow 
spring  cultivation,  than  where  it  is  firmer.  If  the  thrips  are 
disturbed  during  their  first  few  weeks  in  the  ground — for  example, 
by  cultivation — and  if  not  killed,  they  immediately  go  deeper  and 
make  new  cells.  The  larv<e  remain  in  a  dormant  condition,  in 
which   no   food  is  taken,  and  do  not  move  from  their  cells,  unless 


Fig.  15.— The  pear  thrips:  Larva. 
Muchenlarged.  (Author's  illus- 
tration. ) 

ground    immediately 
much    greater   depth 


THE   PEAB   THRIPS   AND   ITS    CONTROL. 


59 


disturbed,  until  the  fall  of  the  year,  when  they  change  to  pupse  and 
their  wings  begin  to  develop. 

The  depth  to  which  these  insects  penetrate  in  well-cultivated  or- 
orchards  may  be  noted  in  the  following 
tables.  In  the  establishment  of  these  rec- 
ords, blocks  of  soil  6  by  6  inches  square  by 
20  inches  deep  were  removed  from  under- 
neath prune  and  pear  trees,  brought  to 
the  laboratory,  and  examined  in  layers, 
inch  by  inch,  the  thrips  in  each  layer  being 
counted.  The  figures  in  each  case  repre- 
sent the  total  of  all  of  the  samples  from 
each  orchard — 6  from  the  Bogen  orchard, 
10  from  the  Landon,  and  4  each  from 
the  Hume  and  Sorosis  orchards.  The 
percentages  represent  what  proportion 
of  the  thrips  are  in  the  soil  above  the 
mentioned  depth  after  which  the  per- 
centage figures  stand.  The  loose  top  soil 
of  about  4  inches  contained  no  thrips. 


Fig.  16.— The  pear  thrips:  Nymph 
or  pupa.  Much  enlarged.  (Au- 
thor's illustration.) 


Table  II. — Proportion  of  larvae  of  pear  thrips  in  ground  at  different  depths;  records 
from  four  orchards  in  the  Santa  Clara  Valley,  California. 


lo.  of  layer. 

Depth. 

Depth  of  larvae  in  soil. 

> 

Bogen  orchard 
(6  samples). 

Landon  orchard 
(10  samples). 

Hume  orchard 
(4  samples). 

Sorosis  orchard 
(4  samples). 

No.  of        Per 
thrips.       cent. 

No.  of        Per 
thrips.       cent. 

No.  of         Per 
thrips.       cent. 

No.  of        Per 
thrips.    1   cent. 

5 

Inches. 
4  to  5 
5to6 
6to7 
7to8 
8to9 
9  to  10 

10  to  11 

11  to  12 

12  to  13 

13  to  14 

14  to  15 

15  to  16 

3 

249   

518  i          25 
829  i          54 
501  |          71 
305             81 
168  !          87 
172    

87    

21    

76    

33    

0    

188    

277             74 
92             88 
38             94 
14             95 

i :::::::: 

2    

2    

3    

1    

0    

1    

6 

29 
39 
45 
71 
58 
41 
26 
25 
17 
12 

7.75 
17.75 
29 

46.75 
61.25 
71.5 
78 
84 

14               12 

7 

55              55 

8 

25               75 

9 

6              80 

10 

8    

11 

9    

12 

6    

13 

1    

14 

0    

15 

1    

16 

4 

0    

Total  number  of  larvae. 

Average  number  larvae 

per  surface  sq.  foot. . . 

370 
266 

2,959    

1 

627    



126    

126    

THE    PUPA. 


The  period  of  pupation  begins  in  September  and  reaches  its  maxi- 
mum during  October,  November,  and  December.  The  insect  is  at 
this  time  forming  its  new  legs,  antennae,  and  wings,  each  appendage 
developing  within  its  own  little  sac  and  hanging  free  at  the  side  of 
the  body   (fig.   16).     A  few  prematurely  forming  pupse  have  been 


60 


DECIDUOUS  .FRUIT  INSECTS  AND   INSECTICIDES. 


collected  during  midsummer,  but  it  is  not  probable  that  these  live 
through  the  year.     They  do  not  mature  to  form  a  second  brood. 

THE    ADULT. 

Adult  thrips  (fig.  17)  are  common  in  the  ground  in  December 
and  January,  but  all  seem  to  await  the  proper  time  in  February 
before  they  come  out.     If  they  are  prematurely  broken  out  from 

their  cells  during  December  or  January 
they  are  active  and  can  fly,  but  they 
never  seem  to   leave  the  ground   at  tins 

time  of  their 
own  accord. 
The  transforma- 
tion from  larva 
to  pupa  and  to 
the  adult  is  a 
slow  and  grad- 
ual  one  and 
occupies  several 
months. 

METHODS  OF  TREATMENT. 
CULTIVATION. 

Many  ideas  have  been  advanced  regarding  the 
value  of  plowing  and  cultivating  at  different 
times  of  the  year  as  remedial  measures  against 
thrips;  especially  during  April  and  May,  when 
the  larvae  are  just  entering  the  ground ;  in  May, 
June,  and  July,  after  they  are  all  in;  in  the  fall 
and  early  winter,  to  destroy  pupae;  and  during 
February  and  March,  when  adults  are  coming 
out.  It  lias  now  been  clearly  demonstrated  that  much  benefit  can  be 
derived  in  checking  the  thrips  by  plowing  and  otherwise  cultivating 
the  ground,  if  this  is  done  at  a  proper  time  and  with  care. 

Thrips  larvae  penetrate  until  they  can  find  a  protected  place  where 
no  1  i ltI i t  enters.  This  may  be  within  2  or  3  inches  of  the  surface,  in 
ground  along  roadways  which  is  not  cultivated  and  which  may  be 
partly  covered  with  grass.  They  usually  rest  in  the  3  or  4  inches  of 
ground  immediately  below  the  loose  top  soil  in  regularly  cultivated 
land,  and  since  they  are  within  S  or  9  inches  of  the  surface,  they  are 
thus  largely  within  t he  reach  of  the  plow.  If,  from  previous  improper 
cultivation,  the  ground  is  full  of  cracks  and  cavities  from  decayed 
weed  stems  <>r  roots,  or  is  full  of  wormholes,  the  larvae  come  into 
these  and  may  then  penetrate  many  inches. 

Cultivation  during  April  and  May,  when  the  thrips  larvae  are 
entering  the  ground,  will  kill  a  few,  but  it  also  disturbs  and  agitates 


Fig.  17.— The  pear  thrips 
Adult.  Much  enlarged 
(Author's  Illustration.) 


THE   PEAR   THRIPS   AND   ITS   CONTROL.  61 

the  others,  which  then  go  deeper.  Continuous  cultivation  in  June 
and  July,  which,  however,  is  not  always  practicable,  would  also  have 
the  same  effect.  It  should  be  remembered  that  these  insects  are  so 
small  that  they  can  easily  remain  inside  of  very  small  clods  and  be 
turned  over  and  over  again  by  cultivation  without  receiving  any  injury. 

The  thrips  are  passing  through  their  pupal  development  in  the 
late  fall  and  early  winter,  and  they  are  then  more  susceptible  to 
mechanical  injury  than  at  any  other  time.  They  are  only  slightly 
active,  and  can  not  build  other  cells  if  once  they  are  forced  frora  the 
old  ones.  Their  new  legs,  antennae,  and  wings  are  sheathed  in  long, 
delicate  sacs,  any  one  of  which  may  easily  be  broken  or  deformed  by 
the  least  disturbance. 

Several  experiments  with  fall  and  winter  plowing  for  thrips  were 
carried  out  in  the  fall  of  1908,  and  the  following  records  show  what 
results  have  been  obtained  in  two  of  these  orchards,  where  special 
attention  was  given  to  securing  data.  Areas  of  20  and  70  acres, 
respectively,  were  plowed  and  harrowed,  and  all  of  the  first,  with  20 
acres  of  the  second,  was  cross  plowed.  This  plowing  was  done 
mostly  during  December,  a  lack  of  early  rains  having  hindered  from 
doing  the  work  sooner.  In  each  case  several  samples  of  soil,  17  by 
17  inches  square  by  20  inches  deep,  were  removed  from  the  orchards, 
both  before  and  after  treatment,  brought  to  the  laboratory  yard, 
and  embedded  to  their  natural  depth  in  the  ground.  The  cages 
remained  open  until  a  time  when  the  adult  thrips  began  to  come  out. 
They  were  then  covered  over,  and  thereafter  a  daily  record  of  the 
emerging  insects  was  made  for  each.  The  blocks  of  soil  were  selected 
from  near-by  trees  and  under  like  conditions,  to  insure  as  far  as  pos- 
sible a  uniform  number  of  thrips  in  each. 

Cages  I,  II,  III,  and  IY  from  the  Landon  orchard  were  taken  from 
land  which  had  been  plowed  and  cross  plowed  in  November  and 
December,  and  cages  V  and  YI,  from  the  same  orchard,  were  taken 
from  under  trees  where  no  winter  plowing  had  been  done.  Cages  YII 
and  YIII,  from  the  Hume  orchard,  were  taken  from  land  which  was 
plowed  and  cross  plowed,  and  cages  IX  and  X  from  untreated  soil. 

Table  III. — Experiments  with  fall  and  winter  plowing  for  the  pear  thrips  in  two  orchards 
in  the  Santa  Clara  Valley,  California. 

LAXDOX  ORCHARD. 

Plowed  and  cross  plowed.  Xot  treated. 


Cage  I. 

Cage  II. 

Cage  III. 

Cage  IV. 

Cage  V. 

Cage  VI. 

Total  number  of  thrips 

Total  number  of  thrips  per  square  foot  of 
surface 

475 
237 

389 
194 

607 
303 

115 
57 

1,175 

1,474 
734 

Average  number  of  thrips  per  cage: 

Cages  I,  II,  III.  and  IV 396 

Cages  V  and  VI 1,324 

Average  number  of  thrips  per  square  foot  of  surface  in  each  cage: 

Treated 198 

Untreated 662 

Percentage  living  in  treated  areas  as  against  the  numbers  of  thrips  in  untreated  ground 30 

Approximate  percentage  killed 70 


62 


DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 


Table  III. 


-Experiments  with  fall  and  winter  plowing  for  the  pear  thrips   in  two 
orchards  in  the  Santa  Clara  Valley,  California — Continued. 


HUME  ORCHARD. 


Plowed  and  cross  plowed. 

Not  treated. 

Cage  VII. 

Cage  VIII. 

Cage  IX. 

Cage  X. 

421 
210 

643 
321 

2,185 
1,092 

1,771 

Tot  nl  iuinibir  of  thrips  per  square  foot  of  surface. 

885 

'o  number  of  thrips  per  cage: 
(aces  VII  and  VIIL. 

265 

Oeges  IX  and  X 

988 

_'o  number  of  thrips  per  square  foot  of  surface  in  i 
Treated 

133 

i  ntreated 494 

Percentage  living  in  treated  areas  as  against  the  numbers  of  thrips  in  untreated  ground 27 

Approximate  percentage  killed 73 

Bearing  in  mind  that  the  larvae  penetrate  into  the  ground  quickly 
after  they  leave  the  trees;  that  they  remain  usually  below  the  loose 
top  soil,  going  deeper  if  disturbed,  and  also  that  they  are  most  sus- 
ceptible to  injury  in  the  pupal  stage,  cultivating  and  plowing  should 
be  so  arranged  as  to  take  best  advantage  of  their  habits,  to  encourage 
their  locating  near  the  surface,  planning  at  the  same  time  to  reach 
them  by  late  fall  and  early  winter  plowing. 

The  principle  of  fall  plowing  is  to  use  a  moldboard  or  disk  plow, 
and  by  turning  the  land  over  to  bring  the  thrips  which  rest  in  the 
lower  strata  of  ground  up  to  the  surface.  The  land  should  then  be 
thoroughly  harrowed  or  worked  over  with  a  disk  cultivator.  With 
the  present  methods  of  plowing,  a  strip  of  2  feet  or  more  of  undis- 
turbed ground  is  usually  left  in  the  tree  row.  It  is  necessary  also  to 
plow  to  a  less  depth  close  under  the  trees  than  in  the  middle  of  the 
rows.  The  land  should  therefore  be  plowed  and  cross  plowed,  to 
insure  breaking  up  all  of  the  ground  to  a  uniform  depth,  and  harrowed 
after  each  plowing,  to  make  the  treatment  thorough. 

The  Landon  orchard  was  uniformly  plowed  to  a  depth  of  about  9 
inches.  It  will  be  seen  by  referring  to  Table  II  that  81  per  cent  of 
all  the  thrips  were  above  this  depth  and  were  therefore  disturbed. 
Table  III  shows  that  there  were  70  per  cent  less  live  thrips  in  ground 
which  had  been  plowed  and  cultivated  than  in  that  which  had 
received  no  winter  treatment.  These  thrips,  about  89  per  cent  of 
all  which  were  disturbed,  must  therefore  have  been  killed  by  the 
cultivating. 

The  Bume  orchard  was  plowed  uniformly  to  a  depth  of  about  7 
inches.  Table  II  shows  that  88  per  cent  of  the  thrips  were  between 
the  .surface  and  this  depth,  and  Table  III  shows  that  about  73  per 
cent  of  the  total  number  of  thrips  in  this  orchard  were  killed  by 
cultivation. 


THE  PEAR  THRIPS  AND  ITS   CONTROL.  63 

Plowing  during  February  and  March,  when  adult  thrips  are  coming 
out  of  the  ground,  is  not  practicable  because  of  the  usually  heavy 
rainfall  at  this  time,  and  because  the  ground  breaks  up  into  large 
instead  of  small  clods,  for  which  reason  only  a  few  thrips  are  killed. 
Then,  too,  plowing  at  this  time  seems  to  let  the  thrips  out  all  at  once, 
thus  increasing  rather  than  reducing  their  injury.  Several  orchards 
that  have  been  kept  under  constant  observation,  which  were  plowed 
during  February  and  early  March,  were  very  much  more  seriously 
injured  than  orchards  of  the  same  variety  of  fruit  immediately 
adjoining  which  were  not  plowed  at  this  time. 

The  benefits  of  plowing  and  cross  plowing  have  been  so  evident 
in  every  one  of  the  several  orchards  treat  eel  that  during  the  spring 
one  could  tell  almost  to  a  row,  by  the  healthful  condition  of  the  trees, 
where  the  plowing  began  and  where  it  ceased. 

A  careful  examination  of  the  soil  under  prune  trees,  after  plowing 
had  been  accomplished,  showed  that  almost  no  thrips  were  present 
until  a  depth  was  reached  where  the  plows  had  not  cut.  Below 
this  point  the  usual  numbers  of  thrips  were  found. 

SPRAYING. 

Spraying  for  thrips  has  proved  wonderfully  successful  wherever 
proper  sprays  have  been  used  and  the  work  done  with  care  and 
thoroughness,  while  indifferent  and  careless  work  or  improper  sprays 
are  absolutely  ineffective.  The  thrips  must  first  of  all  be  reached. 
This  necessitates  high  pressure — 125  to  180  pounds — and  a  rather 
coarse,  penetrating  spray.  It  is  necessary  also  that  the  spray  be 
directed  downward  into  the  buds,  and  not  thrown  at  them  from 
below  or  from  the  sides.  It  should  be  remembered  that  spraying  is 
done,  not  to  drive  the  insects  away  or  to  protect  the  tree  from  any 
possible  future  attack,  but  to  kill  those  insects  which  are  actually 
present  on  the  trees.  It  may  not  be  possible  to  reach  all  of  the 
thrips  which  are  concealed  in  the  buds  even  with  most  careful  spray- 
ing, but  a  very  large  percentage  of  them  can  be  killed.  Spraying 
into  partly  opened  buds  and  blossoms  theoretically  seems  impos- 
sible, but  is  found  entirely  practicable  when  a  coarse,  forceful  spray 
is  thrown  down  directly  against  the  tips.  A  tower  platform  should 
be  built  over  the  spray  wagon  so  that  the  tops  of  large  trees  can  be 
properly  sprayed. 

Almost  all  of  the  standard  spray  formulas  have  been  thoroughly 
tested,  and  all  except  two  have  been  ekminated.  The  bodies  of 
the  thrips,  both  adults  and  larvae,  are  decidedly  oily  and  strongly 
resistant  to  all  sprays  which  do  not  readily  assimilate  the  oil.  For 
example,  the  lime-sulphur  solution,  which  is  very  caustic,  may  be 
thrown  onto  the  thrips,  and  it  will  merely  gather  in  globules  on  their 


64  DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 

bodies  and  not  penetrate  to  kill  them.  Both  larvae  and  adults  have 
been  observed  to  actually  float  around  in  the  ordinary  soap  and  lime- 
sulphur  sprays  with  no  apparent  inconvenience.  Dry  sprays  are  also 
absolutely  ineffective.  Emulsions  of  oil  combined  with  crude  car- 
bolic acid  or  crude  creosote  are  extremely  penetrating,  in  reality  kill- 
ing almost  every  thrips  that  they  touch,  even  when  applied  in  a  very 
weak  form;  but  these  combinations  are  just  as  violently  injurious  to 
blossoms  and  leaves  as  to  thrips,  consequently  they  can  not  be 
considered.  Poisonous  sprays  are  ineffective  because  the  thrips  feed 
from  the  inner  parts  of  the  plant  and  not  from  the  outer  layers,  where 
the  poison  would  be  placed. 

Black-leaf  tobacco  extract  diluted  to  proportions  of  1  part  extract 
to  50  of  water  has  been  very  successful,  but  this  spray  seems  to 
demand  a  somewhat  heavier  and  more  penetrating  liquid  than  water 
alone  as  a  carrying  agent.  The  distillate  oil  emulsion  in  6  per  cent 
dilution  is  almost  as  deadly  as  the  black-leaf  extract,  but  there  will 
follow  some  injury  from  the  spray  unless  conditions  are  altogether 
favorable.  The  oil  spray  has  the  advantage  of  being  heavier,  of 
being  forced  more  easily  into  the  buds,  and  of  penetrating  the  oily 
coating  offered  by  the  thrips.  This  emulsion,  however,  reduced  to  a 
1£  or  2  per  cent  solution,  can  be  applied  with  safety  to  all  trees,  and 
when  combined  with  black-leaf  extract,  diluted  at  the  rate  of  1  part 
of  extract  to  60  or  70  parts  of  water,  furnishes  a  spray  having  all  the 
required  carrying,  penetrating,  and  killing  qualities  desired.  This 
is  the  spray  which  is  now  recommended.  It  can  be  applied  "with 
safety  to  opening  buds,  but  should  not  be  used  on  trees  in  full  bloom. 
Blossom  petals  are  more  sensitive  to  injury  from  spraying  than  any 
other  parts  of  a  tree;  but,  since  they  soon  fall,  the  damage,  although 
noticeable,  is  not  often  serious.  Tins  spray  can  be  applied  to  trees 
immediately  after  the  blossoms  have  fallen,  and  later  to  the  foliage 
for  adults  and  larvse. 

The  first  application  should  properly  be  made  when  the  thrips  are 
coming  from  the  ground  in  large  numbers  and  before  the  cluster  buds 
are  too  far  advanced.  (See  PI.  IV,  showing  stage  of  development  of 
buds  when  first  application  should  be  made.)  This  period  for  the 
San  Jose  district  of  California  is  early  in  March,  but  it  differs,  of 
course,  for  the  several  varieties  of  fruits,  as  stated  on  page  54. 
Where  the  thrips  arc  very  numerous  it  may  be  necessary  to  imme- 
diately follow  this  first  application  with  a  second.  Another  applica- 
tion can  be  made  immediately  after  the  blossom  petals  fall,  to  kill 
the  remaining  adults,  but  more  especially  to  kill  the  larvse.  The 
adults  should  by  all  moans  be  attacked  first.  The  spraying  for  larvse 
is  merely  to  alleviate  the  minor  injury  of  scabbing  on  fruits,  and  to 
protect  the  trees  for  the  following  year  by  killing  the  larvse  before 
they  get  into  the  ground. 


THE  PEAR  THEIPS  AND  ITS  CONTROL.  65 

An  effort  should  be  made  to  kill  all  adults  in  an  orchard  before 
March  15,  when  practically  all  thrips  are  out  of  the  ground  and  when 
oviposition  begins. 

The  black-leaf  tobacco  extract  may  be  purchased  from  local  agents. 
The  distillate  oil  emulsion  can  also  be  purchased  from  local  dealers 
in  spraying  supplies,  but  is  prepared  after  the  following  formula: 

Hot  water gallons. .     12 

Whale-oil  or  fish-oil  soap pounds. .     30 

Distillate  oil  (28°  Baume) gallons..     20 

The  soap  is  first  dissolved  in  a  kettle  of  boiling  water  and  then 
removed  to  the  spray  tank,  where  the  oil  is  added.  This  should  be 
agitated  violently  and  sprayed  out  under  pressure  of  from  125  to  150 
pounds  into  other  barrels.  This  stock  solution  contains  about  55 
per  cent  of  oil,  and  should  be  diluted  at  the  rate  of  about  2  gallons  of 
the  emulsion  to  48  gallons  of  water  for  a  2  per  cent  oil  solution. 

The  secret  of  making  a  thoroughly  good  stock  emulsion  lies  in 
having  the  soap  and  water  boiling  hot,  in  adding  the  oil  to  this  solu- 
tion, and  under  no  circumstances  in  adding  the  soap  and  water  to 
the  oil,  in  thorough  and  violent  agitation,  and,  finally,  in  passing  it 
through  the  spray  nozzles  under  high  pressure.  It  has  been  found 
by  repeated  experiments  that  high  pressure  is  the  most  important 
factor,  and  an  emulsion  passed  once  through  the  pumps  and  nozzles 
under  pressure  of  from  150  to  160  pounds  can  not  be  improved  by 
repeating  this  operation. 

Fish-oil  soap  may  be  made  as  follows: 

Water gallons. .  6 

Lye pounds. .  2 

Fish  oil gallons. .  1| 

Place  the  water  in  a  caldron,  add  the  lye,  and  then  the  fish  oil, 
and  boil  slowly  for  about  two  hours.  This  will  make  about  40  pounds 
of  soap  or  about  a  5-gallon  mixture. 

FERTILIZERS. 

The  numerous  fertilizers  and  soil  fumigants  tested  have  proved 
ineffectual  in  killing  thrips  in  the  ground,  even  when  applied  in  pro- 
portions far  beyond  what  could  be  used  in  ordinary  practice.  It  is 
evident,  however,  that  most  orchards  need  fertilizers  to  strengthen 
the  buds  and  to  insure  a  more  regular  setting  of  fruit.  It  has  been 
demonstrated  repeatedly  with  other  crops  that  soil  soon  deteriorates 
unless  there  is  a  rotation  of  crops  or  unless  fertilizers  are  added. 

IRRIGATION. 

Irrigating  for  thrips  during  any  time  of  the  year  is  entirely  ineffec- 
tual. Their  bodies  are  so  strongly  resistant  to  water  that  while  in 
the  ground  it  is  not  practicable  to  submerge  them  long  enough  to 


66  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 

insure  their  destruction.  Small  areas  containing  thrips  have  been 
submerged  as  long  as  seventy-two  hours,  and  when  examined  a  few 
days  later  all  thrips  wore  alive  and  active. 

SUMMARY. 

The  pear  thrips  has  been  found  only  in  localities  in  the  general  region 
of  San  Francisco  Bay.     Its  presence  in  other  countries  is  not  known. 

The  adults  accomplish  their  feeding  injury  by  rasping  the  tissues 
and  sucking  out  the  plant  juices  in  the  early  buds  and  blossoms. 
Larva?  feed  more  especially  on  the  larger  leaves  and  on  fruits.  Adults 
cause  the  scabbing  on  pears,  while  larvae  produce  the  scabbing  on 
prunes. 

Adults  emerge  from  the  ground  in  late  February  and  early  March, 
just  when  most  trees  are  spreading  their  buds  and  opening  into  bloom. 
Eggs  are  placed  mostly  in  the  blossom  and  fruit  stems  and  in  leaf 
petioles.  The  larvae  hatching  therefrom  feed  for  two  or  three  weeks, 
then  drop  to  the  ground,  where  they  form  a  tiny  protecting  cell 
within  which  they  remain  during  the  rest  of  the  year.  The  pupal 
changes  take  place  within  this  cell  in  the  ground  during  October, 
November,  and  December. 

To  gain  complete  control  of  the  pear  thrips,  both  plowing  and 
spraying  should  be  adopted  as  remedial.  Land  should  be  plowed  as 
soon  as  possible  after  the  early  rains  in  October,  November,  and 
December,  to  a  depth  of  from  7  to  10  inches,  harrowed  or  disked, 
and  then  cross  plowed,  the  second  plowing  to  be  followed  also  by 
harrowing.  The  pupae  are  by  this  means  broken  from  their  pro- 
tecting cells  and  most  of  them  either  injured  or  killed. 

A  combination  spray  of  black-leaf  tobacco  extract  in  the  propor- 
tion of  1  part  of  extract  to  60  parts  of  water  and  2  per  cent  distil- 
late-oil emulsion,  or  a  spray  of  black-leaf  extract  alone,  should  be 
used  against  the  adults  during  early  March,  just  when  the  cluster 
buds  begin  to  open,  and  against  the  larvae  in  April,  after  the  blossom 
petals  fall.  The  thrips  must  be  killed  by  contact  insecticides,  and 
not  by  internal  poisons. 

Fertilizers  and  irrigation  do  not  kill  the  thrips  in  the  ground. 
They  act  against  them  only  indirectly,  by  placing  the  soil  in  better 
condition  for  cultivation  and  by  strengthening  the  trees. 


U.  S.  D.  A.,  B.  E.  Bui.  80,  Part  V.  D.  F.  I.  I.,  September  20,  1910. 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


ON  THE  NUT-FEEDING   HABITS  OF  THE  CODLING  MOTH. 

By  S.  W.  Foster. 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

INTRODUCTION. 

The  codling  moth  (Carpocapsa  pomonella  L.)  has,  up  to  the 
present  time,  been  considered  as  a  serious  enemy  only  to  pome  fruits. 
It  has,  however,  frequently  been  found  in  peaches  and  plums.  There 
are  several  European  records  of  walnut  infestation  by  this  species, 
but  these  reports  were  carefully  sifted  by  Dr.  L.  O.  Howard  in  1887  a 
and  found  to  lack  sufficient  evidence  to  definitely  prove  that  the 
codling  moth  ever  feeds  either  upon  nuts  or  oak  galls.  C.  B.  Simp- 
son6 records  that  Adkin,  in  1895  and  in  1896,  exhibited  specimens 
and  gave  details  as  to  the  rearing  of  this  insect  from  chestnuts.  In 
March,  1908,  at  Siloam  Springs,  Ark.,  the  writer  found  a  full-grown 
larva  of  this  species  with  partially  made  cocoon  inside  a  hickory 
nut,  but  as  there  were  no  signs  of  feeding  on  the  kernel  it  is  probable 
that  the  larva  had  gone  in  only  for  the  purpose  of  hibernation  and 
as  a  safe  place  for  pupating. 

NOTICE  OF  WALNUT  INFESTATION. 

On  October  2,  1909,  while  visiting  the  ranch  of  Mr.  George  Whit- 
man, near  Concord,  Cal.,  the  owner  mentioned  to  the  writer  that 
worms  closely  resembling  the  larvae  of  the  codling  moth  were  doing 
serious  injury  to  the  walnuts  on  one  of  his  trees.  A  large  tree  near 
a  pear-packing  shed  was  closely  examined  and  found  to  have  over 
50  per  cent  of  the  nuts  infested  by  larva?  of  the  codling  moth.  Larva? 
in  all  stages  from  a  few  days  old  to  full  grown  were  found.  Egg- 
shells also  were  found  on  the  outside  of  the  hull  of  the  nuts  and  on 
the  leaves,  indicating  that  the  eggs  had  been  placed  by  the  moth  on 
fruit  and  foliage  promiscuously,  as  is  customary  in  the  case  of  apple 
and  pear. 

a  Rept.  Commissioner  of  Agriculture  for  1887,  pp.  92-94,  1888. 
&  Bui.  41,  Bur.  Ent,  U.  S.  Dept.  Agr.,  p.  19,  1903. 

67 


68  DECIDUOUS   FRUIT   INSECTS    AND    INSECTICIDES. 

NATURE    OF    INJURY. 

The  larva1  upon  hatching  soon  bore  into  the  fleshy  hull  covering 
the  walnut  proper.  Some  individual  Larvae  one-fourth  grown  were 
found  feeding  in  this  hull,  some  burrowing  around  through  the 
fleshy  part,  and  others  tunneling  back  and  forth  on  the  inner  surface 
next  to  the  walnut  shell,  producing  many  little  narrow  furrows  along 
this  inner  surface.  The  majority  of  the  larva?,  however,  go  at  once 
into  the  nut,  entering  always  through  the  fibrous  tissue  connecting 
the  halves  of  the  shell  at  the  base  or  the  stem  end.  The  larvae  may 
bore  into  the  lobes  of  the  kernel  or  feed  on  its  surface.  Some  eat  over 
a  large  portion  next  to  the  shell,  some  follow  along  the  central  area, 
while  others  may  spend  all  the  time  near  the  entrance,  eating  away 
a  larger  portion  of  the  kernel  at  this  place.  In  any  case  the  entire  ker- 
nel is  rendered  rancid  and  unsuited  for  human  consumption.  Plate 
VII,  figure  1,  shows  characteristic  injury  to  the  walnuts  and  Plate 
VII,  figure  2,  a  larva  at  work  in  the  kernel,  the  latter  twice  enlarged. 

EXTENT  OF   INFESTATION. 

Extended  search  throughout  the  central  part  of  Contra  Costa 
County,  Cal.,  showed  the  infestation  to  be  general,  but  light,  except 
where  trees  were  near  packing  sheds,  drying  grounds,  or  adjacent  to  a 
badly  infested  pear  orchard.  Many  trees  were  found  in  such  locali- 
ties showing  from  5  to  25  per  cent  of  the  nuts  infested.  During  the 
winter  of  1909-10  small  quantities  of  walnuts  were  frequently  bought 
in  the  local  markets  and  twice  from  stands  in  San  Francisco  from 
which  codling  moth  larvae  were  secured  and  which  showed  the  char- 
acteristic injury  to  the  kernel.  The  writer  has  also  had  the  same 
experience  with  walnuts  served  on  hotel  and  dining-car  tables.  Mr. 
E.  J.  Hoddy,  of  the  Bureau  of  Entomology,  has  frequently,  during 
the  past  winter,  brought  in  walnuts  from  various  parts  of  the  county 
showing  the  injury  and  presence  of  these  larvae. 

VARIETIES  ATTACKED. 

All  of  the  soft-shelled  French  varieties  of  walnuts  are  subject  to 
infestation,  and  in  fact  any  of  the  soft-shelled  sorts  having  a  fibrous 
tissue  connecting  the  halves  of  the  shell  at  base.  Moths  were  reared 
the  past  season  from  the  Mayette,  Concord,  Franquette.  and  Pari- 
sienne  varieties. 

SEASONAL   HISTORY   OF   THE   CODLING   MOTH    ON   WALNUTS. 

So  far  all  observations  indicate  that  only  the  later  broods  of  larva? 
attack  the  walnuts.  No  walnuts  could  be  found  showing  early  injury, 
that  is,  before  the  shell  hardened.  Assuming  that  the  larval  life  in 
walnuts  is  the  same  in  Length  as  in  apples  and  pears,  the  earliest  date 
of  infestation  would  be  late  August  or  early  September.    The  Bart- 


Bui.  80,  Pa-t  V,  Bureau  of  Entomology,  U.  S.  Deot.  ol  Agriculture. 


Plate  VI 


Fig.  1.— Concord  Variety  of  French  Walnut,  Showing  Character  of  Injury  by 
Larv/e  of  Codling  Moth.    (Original.' 


Fig. 2. —Concord  Variety  of  French  Walnut,  About  Twice  Natural  Size, 
Showing  Larva  at  Work.    (Original.) 


CODLING   MOTH    INJURY  TO   FRENCH   WALNUTS. 


Biif.  80,  PartV,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  VIII. 


Fig.  1.— Concord  Variety  of   French  Walnut,  Showing   Fibrous  Tissue  Con- 
necting the  Halves,  and  Empty  Pupal  Skin.    (Original.'* 


Fig.  2.— Concord  Variety  of    French  Walnut,   Showing   Entrance  and   Exit 
Holes  of  Larva.    (Original.) 


CODLING  MOTH  INJURY  TO  FRENCH  WALNUTS. 


NUT-FEEDING   HABITS   OF   THE   CODLING   MOTH.  69 

lett  pear  crop  around  Concord.  Cal..  is  picked  prior  to  this  time  and 
before  all  the  second-brood  moths  have  developed.  It  is  entirely 
probable  that  these  late-appearing  individuals  seek  the  walnut  as  the 
only  remaining  plant  suitable  for  opposition.  Thorough  search 
during  May  and  June.  1910.  failed  to  show  the  presence  of  any  larva? 
on  trees  that  were  badly  infested  last  season. 

Life  of  larva  in  walnuts. — In  spite  of  the  extreme  bitterness  of  the 
fleshy  hull,  some  larva?  thrive  well  there  for  a  time  before  entering 
the  kernel,  as  several  specimens  of  healthy,  active  larva?  one-fourth 
to  one-half  grown  were  found  in  the  hull.  However,  in  all  cases 
under  observation  the  larva?  left  the  hull  and  entered  the  kernel  be- 
fore reaching  maturity.  The  majority  of  the  larva?  burrow  directly 
through  the  fibrous  tissue  connecting  the  halves  of  the  shell.  Some 
larva?  are  saved  the  necessity  of  burrowing  through  the  hull,  as  this. 
during  the  period  of  infestation,  is  ripening  on  many  of  the  early 
nuts,  and  on  account  of  the  parting  of  the  lobes  the  small  larva  has 
only  to  eat  its  way  through  the  thin  fibrous  connection.  No  case  was 
noted  where  the  larva  entered  through  the  shell. 

Time  required  for  development. — No  individual  records  were  kept, 
but  all  observations  show  that  the  larva  develops  as  rapidly  on  the 
meat  of  the  walnut  as  it  does  in  apples  at  this  season  of  the  year. 
Some  larva?  less  than  a  week  old,  collected  in  walnuts  October  5, 
reached  their  full  development  and  were  spinning  cocoons  by  the 
middle  of  November.  Others,  however,  continued  to  do  more  or  less 
feeding  on  the  kernel  and  did  not  spin  cocoons  until  January. 

Hibernation. — From  1  gallon  of  infested  walnuts  kept  at  the 
laboratory  perhaps  one-fourth  of  the  larva?  cocooned  and  pupated 
inside  the  shell.  Others,  leaving  the  walnuts  at  the  same  place  where 
they  entered — that  is.  through  the  fibrous  tissue  connecting  the  halves 
of  the  shell — pupated  in  bits  of  paper  and  rags  kept  in  the  jars. 
Before  pupating  in  the  walnuts,  the  larva  prepares  an  opening 
through  the  fibrous  tissue  sufficient  for  the  exit  of  the  moth  and  spins 
its  cocoon  immediately  adjoining  this  opening.  Upon  the  emergence 
of  the  moth  the  shed  pupal  skin  is  left  outside  on  the  end  of  the 
walnut,  as  is  shown  in  Plate  VIII.  figure  1.  All  larva?  under  observa- 
tion pupated  between  February  20  and  April  10. 

Adults. — Moths  emerged  in  numbers  from  the  above  material  dur- 
ing April  and  May.  1910.  comparing  closely  with  the  emergence 
record  of  moths  from  a  quantity  of  overwintering  larva?  taken  from 
bands  on  apple  trees  the  previous  season. 

Identification. — Numerous  adults  emerging  from  this  material 
were  submitted  to  Mr.  August  Busck.  of  the  Bureau  of  Entomology, 
for  identification.  Mr.  Busck  has  definitely  determined  these  as 
Carpocapsa  pomonella  L. :  he  states  that  the  European  Carpocapsa 
putaminana  Staudinger,  recorded  as  feeding  on  walnuts  in  Europe, 
is  now  regarded  as  a  variety  of  pomonella. 


70  DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 

CONTROL. 

As  many  of  the  larvae  eat  their  way  through  the  fleshy  hull  cover- 
ing of  the  walnut,  it  is  probable  that  a  thorough  spraying  with 
arsenate  of  lead  in  the  month  of  August  would  greatly  reduce  the 
infestation.  This  treatment  would  apparently  be  as  effective  in 
destroying  larva?  from  eggs  placed  promiscuously  over  the  foliage 
and  nuts  as  in  the  case  of  the  apple.  From  the  fact  that  many  of 
the  larva1  gain  entrance  to  the  walnut  after  the  hull  has  parted  at 
the  tip,  the  poison  would,  of  course,  not  be  effective  against  these. 
The  infestation  can,  no  doubt,  be  greatly  reduced  by  maintaining 
the  packing  shed  and  drying  grounds  some  distance  from  the  walnut 
grove. 

It  is  the  practice  of  many  pear  growers  to  save  all  windfalls  in 
the  orchard  and  culls  from  the  packing  shed.  These  pears  are  either 
stored  in  large  trays,  stacked  in  the  shade,  or  else  the  pears  are 
covered  with  straw  in  layers  on  the  ground.  As  a  rule,  the  culls 
from  the  packing  ground  are  nearly  all  infested  with  immature 
larvae  of  the  codling  moth,  which  reach  their  full  development  and 
produce  moths  during  the  ripening  period  of  the  walnuts.  This, 
in  most  cases,  is  the  source  of  infestation  of  walnut  groves  found 
to  be  most  seriously  troubled  with  the  codling  moth. 


U.  S.  D.  A.,  B.  E.  Bui.  80,  Part  VI.  D.  F.  1. 1.,  November  28, 1910. 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


LIFE  HISTORY  OF  THE  CODLING  MOTH  IN  NORTHWEST- 
ERN PENNSYLVANIA. 

By  A.  G.  Hammar, 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

INTRODUCTION. 

In  1907  the  section  of  deciduous  fruit  insect  investigations  of  the 
Bureau  of  Entomology  established  at  North  East,  Pa.,  a  temporary 
field  station,  for  the  investigation  of  certain  orchard  and  vineyard 
pests.  One  of  these,  the  codling  moth  (Carpocapsa  pomonella  L.),  has 
been  studied  for  the  three  consecutive  years  of  1907,  1908,  and  1909. 
The  rearing  work  during  the  first  two  seasons  covered  only  the  more 
important  features  in  the  development  of  the  insect,  while  in  1909 
efforts  were  made  to  rear  the  insect  throughout  the  seasons  and  to 
determine  the  time  and  relative  occurrence  of  the  various  stages  of 
the  two  broods. 

In  1907  the  work  was  carried  out  by  Mr.  P.  R.  Jones  of  this  bureau, 
and  in  1908  and  1909  by  the  writer,  who  during  the  last  season  was 
assisted  by  Mr.  Edwin  Selkregg,  of  North  East,  Pa.  Mr.  Fred  John- 
son, of  this  bureau,  has  for  the  three  seasons  contributed  to  this 
work  numerous  field  observations.  All  of  these  studies  have  been 
made  under  the  direction  of  Mr.  A.  L.  Quaintance,  in  charge  of  de- 
ciduous fruit  insect  investigations. 

In  the  presentation  of  the  life-history  studies  the  separate  stages 
of  the  two  generations  are  first  considered  in  detail  as  observed  in 
1909.  Later  are  described  certain  fluctuations,  found  in  regard  to 
the  time  of  emergence  of  moths,  the  time  of  maturity  of  larvae  of  the 
two  broods,  and  also  a  comparison  of  relative  occurrence  of  larvae  of 
the  two  broods  for  the  three  seasons  under  consideration. 

The  term  "brood"  is  here  used  in  speaking  of  individuals  of  one 
generation  of  any  stage,  as  egg,  larva,  or  pupa.  A  generation 
naturally  includes  all  the  stages  of  the  life  cycle,  and  is  considered 
to  begin  with  the  egg  stage  and  to  terminate  with  the  moth  or  imago 
stage  of  the  same  generation. 

30490°— Bull.  80—12 6  71 


72  DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 

SEASONAL-HISTORY  STUDIES  OF  1909. 
ROE    OF    REARING    MATERIAL. 

The  main  portion  of  the  rearing  material  used  in  the  spring  of  1009 
was  collected  during  the  previous  summer  and  fall  from  banded  apple 
tree-:  the  rest  a  small  fraction — constituted  reared  specimens  from 
experiments  of  the  previous  year.  The  larvae  intended  for  pupal 
records  were  allowed  to  make  their  cocoons  between  narrow  strips  of 
wood  (fig.  18),  where  their  transformation  could  be  readily  observed 
without  greatly  altering  their  conditions,  while  those  for  emergence 
records  of  the  moths  cocooned  in  masses  of  old  bark  of  apple  trees. 
During  the  winter  the  material  was  kept  in  a  medium-sized  glass  jar, 
covered  with  thin  cloth,  and  was  thus  left  undisturbed  in  an  open 
shelter  (see  Plate  IX)  until  the  following  spring. 


Fig.  18.— Device  consisting  of  strips  of  wood  held  together  by  rubber  bands  used  in  obtaining  pupal 
records  of  the  codling  moth  (  Oarpocapsa  pomonella).    Reduced.    (Original.) 

The  rearing  material  for  the  following  emergence  of  moths,  or 
first-brood  moths,  was  mainly  from  that  used  in  taking  the  band 
records  of  1909,  and,  to  a  small  extent,  from  reared  specimens.  There 
is  a  special  value  in  the  use  of  band-collected  larva?  in  the  rearing  of 
the  codling  moth,  in  that  these  have  up  to  the  time  of  transforming 
developed  normally  in  the  field  and  the  resulting  adults  show  thus 
both  the  normal  time  of  emergence  and  the  relative  occurrence  in  the 
field. 

OVERWINTERING    LARVJE. 

The  overwintering  lame  of  the  codling  moth  in  the  vicinity  of 
North  East .  Pa.,  are  partly  of  the  first  and  partly  of  the  second  broods. 
As  i->  more  fully  considered  on  page  84,  a  portion  i)\'  the  first-brood 
larva\  unlike  the  Pest,  hibernate  as  do  normally  all  larvie  of  the 
second    brood— and    complete    their   life   cycle    the  following  spring. 


Bui.  80,  Pat  VI,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  IX. 


CODLING   MOTH   IN    NORTHWESTERN   PENNSYLVANIA. 


73 


Unless  reared,  the  larvae  of  the  two  broods  can  not  be  separated  and 
are  simply  referred  to  as  overwintering  larvae.  Similarly  the  resulting 
pupae  and  moths  in  the  spring  originate  from  the  two  separate  broods 
of  the  previous  year's  larvae,  and  these  are  spoken  of  as  "  spring-brood 
pupae''  and  " spring-brood  moths." 


SPRING    BROOD    OF   PUP^. 

Time  of  pupation. — In  the  rearing  cages  the  first  observed  pupation 
took  place  May  24.  Considering,  however,  the  time  of  the  earliest 
record  for  the  emergence  of  moths,  and  the  duration  of  the  pupal 
stage,  which  at  that  time  of  the  season  lasted  24  days,  it  is  probable 
that  pupation  must  have  begun  as  early  as  May  20.  The  last  larvae 
of  the  wintering  broods  pupated  June  25.  The  pupation  period  thus 
covered  a  length  of  time  of  over  one  month  (fig.  22).  Since  the  last 
moth  of  the  spring  brood  emerged  July  17,  pupae  were  in  evidence 
from  May  20  to  July  17. 

Length  of  spiking  pupal  stage. — In  cage  experiments,  records  were 
obtained  of  the  duration  of  the  pupal  stage  for  50  individuals.  (See 
Table  I.) 

Table  I  — Length  of  pupal  periods  in  spring  brood  from  wintering  larvae,  collected 
during  1908,  on  banded  trees. 


No. 

Date  of— 

Days. 

No. 

Date  of— 

Days. 

Pupa- 

Emer- 

Pupa- 

Emer- 

tion. 

gence. 

tion. 

gence. 

1 

May  24 

June  17 

24 

28 

May  29 

June  21 

23 

2 

May  25 

June  16 

22 

29 

May   30 

June  22 

23 

3 

...do 

June  19 

25 

30 

...do 

June  17 

18 

4 

...do 

June  28 

34 

31 

May  31 

June  22 

22 

5 

May   26 

June  17 

22 

32 

...do 

...do 

22 

6 

...do 

June  20 

25 

33 

...do 

...do 

22 

7 

May  27 

...do 

24 

34 

...do 

June  21 

21 

8 

...do 

...do 

24 

35 

...do 

...do 

21 

9 

...do 

...do 

24 

36 

June    1 

June  23 

22 

10 

...do 

June  27 

31 

37 

...do 

...do 

22 

11 

...do 

June  20 

24 

38 

...do 

...do 

22 

12 

...do 

...do 

24 

39 

...do 

...do 

22 

13 

...do 

...do 

24 

40 

June    2 

...do 

21 

14 

...do 

June  14 

18 

41 

...do 

...do 

21 

15 

...do 

June  20 

24 

42 

...do 

...do 

21 

16 

...do 

...do 

24 

43 

...do 

...do 

21 

17 

...do 

...do 

24 

44 

June  17 

July     2 

15 

18 

...do 

June  14 

18 

45 

...do 

July     3 

16 

19 

May   28 

June  19 

22 

46 

...do 

July     4 

17 

20 

...do 

June  20 

23 

47 

June  18 

...do 

16 

21 
22 

...do 

...do 

...do 

June  21 

23 

24 

48 
49 

June  20 
...do 

23 

...do 

June  20 

23 

50 

...do 

24 

...do 

June  16 

19 

51 

June  21 

'July  "6" 

"is" 

25 

...do 

June  21 

24 

52  '  June  23 

July     8 

15 

26 
27 

May  29 
...do 

...do 

...do 

23 
23 

53     June  25 

1 



639 

43S 

Total 

1,077 

74 


DE<  IDUOUS   FRUIT  INSECTS  AND   INSECTICIDES. 


rPho  variations  in  the  length  of  the  pupal  periods,  as  shown  in 
Table  II,  extended  from  15  to  30  days. 

Table  II. — Spring  brood  of  pupse.     Variations  in  the  length  of  the  pupal  periods  as 

recorded  in  Table  I. 


Pupa;. 

Days. 

Pupae. 

Days. 

3 

15 

10 

22 

2 

16 

7 

23 

1 

17 

12 

24 

3 

18 

2 

25 

1 

19 

1 

31 

6 

21 

1 

34 

The  length  of  the  stages  were  especially  prolonged  during  the  early 
part  of  the  period  of  pupation  and  shortest  toward  the  close  of  the 
period,  due  to  a  difference  in  the  temperature.  In  Table  III  is 
given  a  summary  of  the  observations  recorded  in  Table  I,  showing 
an  average  pupal  period  of  22  days  for  the  total  number  of  observa- 
tions. 

Table  III. — Spring  brood  of  pupse.    Summary  of  pupal  periods  of  Table  I. 


Observations. 

Days. 

Average 

21.98 

34 

15 

Maximum 

Minimum 

SPRING    BROOD    OF    MOTHS. 

Time  of  emergence  of  moths  in  the  spring. — In  figure  19  is  shown 
graphically  the  time  of  emergence  and  the  relative  occurrence  of 
moths  of  the  spring  brood.  The  records  for  these  observations  are 
given  in  Table  IV. 

Table  IV. — Emergence  of  spring  moths,   1909,  from  wintering  material  collected  on 

banded  trees  during  1908. 


Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

Date. 

Number 
cf  moths. 

Date. 

Number 
of  moths. 

June  12 
June  13 
June  14 

June  15 
Juno  It, 
Juno    17 
June  18 
Jane  19 
June  20 

1 

June  21 
June  22 

June  23 
June  24 
June  25 
Juno  26 
Juno  27 
June  28 
Juno  28 

31 
23 
50 
40 
50 
83 
32 
35 
30 

June  30 
July     1 
July     2 
July     3 
July     4 
July     5 
July     6 
JulV      7 
July     8 
1 

13 
25 
15 
3 
5 
10 
6 
8 
4 

July     9 
July   10 
JulV    11 
July    14 
July   17 

4 

1 
2 
1 

6 

3 
6 
18 

1 

10 
24 

486 

Indoors,  mollis  were  observed  previous  to  June  12,  but  since  these 
undoubtedly  had  wintered  in  the  bouse  their  appearance  docs  not 
represent  normal  conditions,  as  is  believed  to  be  the  case  with  mate- 


CODLING   MOTH  IN    NORTHWESTERN   PENNSYLVANIA. 


75 


rial  which  had  been  kept  out  of  doors  during  the  winter.  The  emer- 
gence reached  its  maximum  on  June  23  and  24,  and  on  July  17  the 
last  moth  emerged. 

Time  of  emergence  of  moths  in  the  spring  versus  the  time  wintering 
larvse  leave  the  fruit  the  preceding  year. — In  Table  V  is  given  a  detailed 


Fig.  19.— Emergence  curve  showing  spring-brood  moths  in  1909,  at  North  East,  Pa.    (Original.. 

account  of  the  band  records  of  1908,  including  the  dates  of  collecting, 
which  extend  from  July  18  to  November  9,  and  the  daily  emergence 
records  of  moths  in  the  spring  of  1909  for  the  17  separate  band  col- 
lections. 


76 


DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 


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CODLING   MOTH  IN   NORTHWESTERN    PENNSYLVANIA. 


77 


The  wintering  larvse  belonged  to  both  the  first  and  the  second 
broods.  It  will  be  seen  by  a  glance  at  Table  V  that  there  was  no 
marked  difference  in  the  time  of  emergence  of  moths  from  the  first 
and  the  second  brood  larvae.  The  division  line  between  the  two 
broods  can  be  approximately  determined  as  between  August  29  and 
September  5,  as  shown  in  figure  27. 

Time  during  the  day  when  moths  emerged. — When  only  one  daily 
record  of  the  emergence  of  the  moths  is  taken,  it  is  of  importance  to 
know  the  time  when  most  moths  emerge.  A  few  observations,  taken 
hourly,  June  24,  from  8.30  a.  m.  to  8.30  p.  m.  the  same  day,  and 
continued,  June  26,  from  4.30  a.  m.  to  9.30  a.  m.,  are  recorded  in 
Table  VI. 


Table  VI. — Spring  brood  of  moths.     Time  of  emergence  during  the  day. 


Time  of  observation. 

Emer- 
gence of 

moths. 

Time  of  observation. 

Emer- 
gence of 
moths. 

Time  of  observation. 

Emer- 
gence of 
moths. 

Date. 

Hour. 

Date. 

Hour. 

Date. 

Hour. 

June  24 
Do...- 
Do.... 
Do.... 
Do.... 
Do.... 
Do.... 

8.30  a.m.. 
9.30  a.  m. . 

3 

June  24 

Do.... 

Do.... 

Do.... 

Do.... 

Do.... 
June  26 

3.30  p.  m.. 

June  26 
Do.... 
Do.... 
Do.... 
Do.... 
Do... 

4.30  a.  m  . 

4.30  p.  m.. 

5.30  a.  m.. 

10.30  a.  m. 
11.30  a.  m. 
12.30  p.m. 
1.30  p.  m.. 
2.30  p.  m  . 

5.30  p.  m . . 

6.30  a.  m.. 

1 
2 

1 

6.30  p.m.. 
7.30  p.  m . . 
8.30  p.  m.. 

7.30  a.  m.. 
8.30  a.m.. 
9.30  a.  m.. 

1 

1 

Nine  moths  emerged  during  this  period.  The  first  emergence  took 
place  about  7.30  a.  m.  and  the  last  about  1.30  p.  m.  During  the  after- 
noon, evening,  and  night  no  moths  emerged.  More  observations  on 
this  habit  of  the  moths  are  desirable  in  order  to  establish  more  accu- 
rately the  time  limits  during  the  day  when  moths  emerge.  The 
above  observations,  however,  suggest  the  general  tendency.  Pos- 
sibly the  varying  temperature  and  moisture  conditions  of  the  day 
are  influencing  factors,  because  after  the  process  of  emerging  the  parts 
of  the  body,  and  particularly  the  wings,  must  expand  quickly  and 
assume  a  normal  shape  before  hardening;  in  case  of  extreme  dryness 
the  wings  may  fail  to  expand. 

Period  of  oviposition. — The  moths  in  confinement  frequently  fail  to 
oviposit,  which  is  especially  the  case  when  a  single  pair  or  only  a  few 
individual  moths  are  kept  together.  During  the  season  of  1909  an 
abundance  of  eggs  was  obtained  from  moths  confined  in  numbers  of 
from  10  to  40  in  medium-sized  glass  jars  covered  with  tiiin  cloth. 
Each  jar  contained  a  layer  of  moist  sand;  food,  consisting  of  brown 
sugar  and  honey;  and  for  oviposition,  apples  and  apple  twigs  with 
foliage  were  supplied  daily.  As  has  been  observed  by  other  inves- 
tigators, the  eggs  are  laid  during  the  evening  and  the  night.  In  one 
instance  a  moth  was  observed  in  the  act  of  ovipositing  about  9 
o'clock  in  the  morning.  The  eggs  were  placed  in  abundance  on  the 
apples,  the  branches,  and  the  foliage,  and  even  on  the  bottom  and  on 


78 


DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 


the  sides  of  the  jar.  The  apples  and  foliage  were  daily  removed  and 
replaced  by  fresh  material,  and  to  avoid  infestation  from  hatching 
eggs,  which  had  been  placed  on  the  sides  and  bottom  of  the  jars, 
it  became  necessary  to  transfer  the  moths  twice  a  week  into  new 
jars,  the  old  ones  being  thoroughly  cleaned  before  being  put  to  fur- 
ther use. 

In  Table  VII  have  been  recorded  the  results  from  observations  on 
oviposit  ion  in  12  rearing  jars  by  moths  of  a  given  age.  In  no 
instance  did  oviposition  take  place  until  2  days  after  the  emergence 
of  the  moths,  and  on  an  average  the  eggs  were  first  laid  during  the 
fourth  day  after  emergence. 

Table   V 1 1 .     Oviposition  periods  of  spring-brood  moths  in  rearing  cages. 


Cage  no. 

Number 

of  moths. 

Date  of— 

Days— 

Emer- 
gence of 
moths. 

First  ovi- 
position. 

Last  ovi- 
position. 

Before 
oviposi- 
tion. 

Length 
of  ovipo- 
sition. 

Between 
emer- 
gence 
and  last 
oviposi- 
tion. 

1 

2 
3 
4 
5 

6 
7 
8 
9 
10 
11 
12 

7 

10 
10 
17 
11 
10 
39 
18 
37 
23 
15 

4 

June  16 
June  17 
June  19 
June  20 
June  21 
June  22 
June  23 
June  24 
June  25 
June  29 
July     1 
July     7 

June  23 
June  27 
June  24 
June  23 
June  24 
June  25 

...do 

June  27 

...do 

July     7 
July     5 
July   12 

June  25 
June  29 
June  24 
June  30 
June  29 
July     1 
July     6 
July     5 
July     7 
July   15 

...do 

July  21 

7 

10 
5 
3 
3 
3 
2 
3 
2 
8 
4 
5 

3 
3 

1 
8 
6 
7 

12 
9 

11 
9 

11 

10 

9 
12 

5 
10 

8 

9 

13 
11 
12 
16 
14 
14 

201 

55 

90 

133 

The  length  of  oviposition  for  each  jar  varied  from  1  to  11  days, 
with  an  average  of  7  days  for  the  entire  number  of  rearing  jars.  In 
one  instance  oviposition  took  place  the  sixteenth  day  after  the  date 
of  emergence  of  the  moths.  On  an  average,  however,  oviposition 
extended  to  11  days  after  emergence. 

Table  VIII. — Oviposition  periods  of  spring-brood  moths.    Summary  of  Table  VII. 


Observations. 

Days  be- 
fore ovi- 
position. 

Days  of 
oviposi- 
tion. 

Days   be- 
tween emer- 
gence and 
last  ovi po- 
sition. 

4.6 

10 
2 

7.5 
12 

11.08 

16 
5 

In   view  of  the  abundance  of  eggs  deposited  and  the  manner  in 

which  the)  were  laid,  it  was  impossible  to  determine  the  number  for  a 

given  moth.     Jn  the  field  the  relative  abundance  of  eggs  during  the 

on  must   be  approximately  in  proportion  to  the  occurrence  of 

moths  (fig.  19).      In  the  rearing  jars  eggs  were  obtained  from  June  23 


CODLING   MOTH  IK   NORTHWESTERN   PENNSYLVANIA. 


to  July  15.  Considering,  however,  the  above  observations  on  opposi- 
tion and  the  time  of  emergence  of  the  first  moths,  it  can  closely  and  with 
some  degree  of  accuracy  be  estimated  that  eggs  were  laid  in  the  field 
from  about  June  17  to  about  July  22. 

Length  of  life  of  the  moth. — Records  were  kept  relative  to  the  length 
of  life  of  the  moths  which  were  confined  in  jars  for  oviposition.  The 
results  of  these  observations  are  given  in  Table  IX,  with  a  summary 
in  Tables  X  and  XI  showing  the  extent  of  variation  in  the  length  of 
life  of  161  moths. 

Table  IX. — Length  of  life  of  moths  of  the  spring  brood  in  rearing  cages. 


Number 
of  moths. 

Date  of— 

Number 
of  moths. 

Date  of— 

EmeI"       Death. 

Days. 

5S2"       Death. 

Days. 

gence.    i 

gence. 

6 

June  21 

July     2 

n 

1 

June  25 

July   12 

17 

3 

...do 

July     4 

13 

1 

...do 

Julv   14 

19 

2 
6 

.do.... 

16 
10 

5 

June  29 

July   10 

11 
12 

June  22     July     2 

2 

...do 

July   11 

3 

...do July     3 

11 

5 

...do 

July   12 

13 

1 

...do '  Julv     9 

17 

2 

...do 

July   13 

14 

21 

June  23     July     2 

9 

2 

...do 

Julv   14 

15 

2 

...do 

July    3 

10 

2 

...do 

July   15 

16 

4 

...do 

July     4 

11 

5 

...do 

July   16 

17 

6 

...do 

July     5 

12 

4 

Julv     1 

July   11 

10 

5 

...do i  July   10 

17 

5 

...do 

July   12 

11 

1 

...do 

July   12 

19 

2 

...do 

July   13 

12 

10 

June  24 

Julv     1 

7 

3 

...do 

July   15 

14 

4 

...do 

July     5 

11 

1 

...do 

July   16 

15 

2 

...do 

July     7 

13 

4 

July     5 

July   12 

7 

10 

June  25 

July     2 

7 

2 

...do 

July   14 

9 

7 

...do 

July     5 

10 

2 

...do 

July   16 

11 

7 

...do 

July     6 

11 

1 

...do 

July  20 

15 

4 

...do 

July     7 

12 

1 

...do 

July  22 

17 

1 

...do 

July     9 

14 

2 

July     7 

July   16 

9 

1 

...do 

July   10 

15 

1 

...do 

July   17 

10 

1 

...do !  July  11 

16 

1 

...do 

July   22 

15 

Table  X. — Length  of  life  of  moths  of  the  spring  brood.     Summary  of  Table  IX. 


Number 
of  moths. 

Days  per 
moth. 

Days  for 

total 
number 
of  moths. 

Number  |  Days  per 
of  moths.  1    moth. 

Days  for 

total 
number 
of  moths. 

24 
25 
20 
36 
14 
10 
6 

9 
10 
11 
12 
13 
14 

168 
225 
200 
396 
168 
130 
84 

6 
5 
13 
2 

15 
16 
17 
19 

90 

80 

221 

38 

161 

1,800 

Table  XI. — Length  of  life  of  moths  of  the  spring  brood.     Summary  of  Table  IX. 


Observations. 

Days. 

Average 

11.18 
19 
7 

Maximum 

It  is  evident  from  this  table  that  the  greater  number  died  shortly 
after  the  first  week  after  emergence.  On  an  average  the  moths  lived 
11  days;  2  moths  lived  19  days  and  24  moths  lived  7  days. 


80 


DECIDUOUS  FRUIT  INSECTS   AND   INSECTICIDES 


THE    FIRST    GENERATION. 


FIRST-BROOD    EGGS. 


Incubation  period. — In  the  preceding  pages  the  time  and  extent  of 
egg  deposition  have  been  considered  as  habits  of  the  moths.  In  view 
of  the  abundance  of  eggs  laid  on  the  apples  in  the  cages,  it  was  not  pos- 
sible to  count  the  eggs  and  determine  the  incubation  period  for  individ- 
ual eggs.  But,  as  shown  in  Table  XII,  records  were  taken  at  the  time 
of  hatching  of  the  first  and  the  last  eggs  of  each  group  of  apples  con- 
taining  eggs  of  a  given  age,  which  merely  shows  in  a  general  way  the 
extent  of  the  variability  during  the  incubation. 

Table  XII. — First-brood  eggs.     Incubation  period  of  eggs  laid  in  rearing  cages. 


No. 
of  obser- 
vation. 

Date  of— 

Days  of 
incuba- 
tion. 

No. 

of  obser- 
vation. 

Date  of— 

Days  of 
incuba- 
tion. 

Deposi- 
tion. 

Hatch- 
ing. 

Deposi- 
tion. 

Hatch- 
ing. 

1 

2 

3 

4 

5 

6  .    ... 

June  23 
June  24 
June  25 

...do 

June  26 

...do 

June  29 

...do 

July     1 
July     2 

...do 

July     3 
July     4 
July     5 
July     6 
July     7 
July     8 
July     9 
July     8 
July     9 
July   10 
July    11 

...do 

July    12 

(') 

5 

G 

7 

6 

7 

7 

8 

8 

8 

9 
10 

8  1 

8 

9 
10 

9 
10  | 

19 

20 

21 

22 

23 

24 

25 

July     3 
Ju!v     4 
July     5 

...do 

July     6 
July     8 

...do 

July   12 

...do 

...do 

July    13 

...do 

July    14 
July    15 

...do 

...do 

July    16 

...do 

July    17 
July    18 
July    19 
July   21 

...do 

July   22 

...do 

9 

8 
7 
8 
7 
6 
7 
6 
5 
6 
S 
6 
6 
7 
8 
7 
8 
7 

7 

8 

June  27 
...do.... 

26 

27 

28 

July     9 
July    10 
...do 

9 

10 

11 

June  28 
June  29 
...do.... 

29 

30 

July    11 
...do 

12.. 

...do.... 

13 

14 

15  . 

June  30 
July     1 
...do 

31 

32 

July    12 
...do 

33 

34 

35 

36 

July    13 
July    14 

...do 

July    15 

16 

17 

18 

...do 

July     2 
...do 

The  difference  of  one  to  two  days  in  the  time  of  hatching  indicates 
an  existing  difference  in  the  embryological  development  originating 
previous  to  the  time  of  oviposition.  Similar  observations  were  made 
in  1909  by  the  writer  with  eggs  of  the  grape  root-worm  which  had  all 
been  laid  by  a  single  female  at  the  same  time.  On  hatching,  these 
eggs  showed  a  variation  of  2  days  in  the  time  of  incubation.  Table 
XII,  representing  a  summary  of  observations  of  the  previous  table, 
shows  an  average  of  7.33  days  for  the  entire  egg  period,  with  a  maxi- 
mum of  10  days  and  a  minimum  of  5  days. 

Taiu.k  XIII.     Incubation  period  of  first-brood  eggs.     Summary  of  Table  XII. 


Observations. 

Days  of 
incuba- 
tion. 

7.33 
10 
5 

Miixiiiumi 

Minimum 

CODLING   MOTH  IN   NORTH  WESTERN   PENNSYLVANIA.  81 


FIRST-BROOD   LAR\\£. 


As  has  been  already  stated,  some  of  the  first-brood  larvae  do  not 
transform  with  the  rest  of  the  brood,  but  spin  up  for  the  winter,  hiber- 
nating along  with  second-brood  larvae.  In  the  rearing  of  the  codling 
moth  separate  observations  were  made  for  the  two  sets  of  larvae, 
which  are  here  treated  separately  as  "transforming"  and  " wintering" 
larvae. 

Time  of  hatching. — In  the  rearing  cages  the  first  larvae  hatched 
June  30,  but  these  were  not  from  eggs  of  the  earliest  moths,  as  the 
latter  failed  to  oviposit  in  captivity.  Considering,  however,  the 
emergence  and  oviposition  records  of  the  moths,  previously  described, 
it  is  very  probable  that  eggs  occurred  in  the  field  on  June  23  and 
continued  to  appear  until  the  end  of  July.  In  the  rearing  cages  the 
last  larvae  of  the  brood  hatched  June  22,  while  in  the  field  two  newly 
hatched  larvae  were  found  in  apples  as  late  as  July  25. 

Number  of  larvx  developing  in  each  apple. — In  the  rearing  of  the 
codling  moth  great  numbers  of  young  larvae  entered  the  same  apple, 
but  when  the  apples  were  examined  at  the  time  of  maturity  of  the 
larvae  only  one  or,  rarely,  two  or  three  larvae  were  found  in  the 
same  fruit.  In  orchards  usually  only  a  single  larva  is  found  in  each 
apple,  although  the  apples  may  show  several  empty  eggshells  and 
entrance  places  of  the  young  larvae.  The  writer  observed,  on  July 
2,  1909,  in  the  course  of  rearing  the  grape-berry  moth  (Polychrosis 
viteana  Clemens),  how  a  newly  hatched  larva  devoured  another  of 
its  own  kind,  both  having  emerged  at  about  the  same  time.  It  is 
very  probable  that  where  larvae  of  the  codling  moth  occur  in  num- 
bers many  of  them  meet  a  similar  fate. 

Period  of  feeding  of  transforming  larvx. — In  Table  XXII  are  given 
the  feeding  periods  of  53  individual  larvae  which  were  reared  in 
cages.  On  an  average  the  larvae  remained  in  the  fruit  26  days,  a 
single  larva  remained  37  davs,  while  the  shortest  period  in  the  fruit 
was  17  days.     (See  Table  XXIII.) 

Period  of  feeding  of  wintering  larvse  of  the  first  brood. — On  an  aver- 
age the  wintering  larvae  of  the  first  brood  remained  31  days  in  the 
fruit,  while  the  transforming  larvae  remained  only  26  days.  (See 
Table  XVI.)  Records  of  the  feeding  period  for  about  200  winter- 
ing larvae  were  taken  from  observations  in  rearing  cages,  as  shown 
in  Table  XIV. 


82  DECIDUOUS   FRUIT  INSECTS  AND  INSECTICIDES. 

Table  XIV. — Larvae  of  the  first  brood.     Feeding  periods  of  wintering  larvae. 


*o 

Date- 

i 

*o 

Date- 

J38J 

a 

b§ 

2t 

Hatched. 

Led 

fruit. 

eo 

s 

Hatched. 

Left 

fruit. 

50  J 

03 

0 

June  30 

July   25 

25 

July     8 

Aug.    5 

28 

...do 

July   28 

28 

...do 

Aug.     6 

29 

...do 

July   30 

30 

...do 

Aug.     8 

31 

...do 

July   31 

31 

...do 

Aug.  10 

33 

...do 

Aug.     9 

40 

...do 

Aug.   11 

34 

...do.... 

Aug.  11 

42 

...do 

Aug.  12 

35 

...do 

July   29 

29 

...do 

Aug.  13 

36 

...do 

July   30 

30 

July     9 

July   28 

a  19 

...do 

July   31 

31 

...do 

Aug.     2 

24 

July     1 

July   20 

25 

3 

...do 

Aug.     3 

25 

...do 

July   29 

28 

2 

...do 

Aug.     4 

26 

...do 

July   31 

30 

3 

...do 

Aug.     9 

31 

...do 

Aug.    2 

32 

2 

...do 

Aug.  15 

37 

...do 

Aug.     4 

34 

...do 

Aug.  28 

50 

...do 

Aug.  17 

47 

July   10 

July   26 

a  16 

July     2 

July   31 

29 

...do 

Aug.     4 

25 

...do 

Aug.     2 

31 

...do 

Aug.     5 

26 

...do 

Aug.     5 

34 

...do 

Aug.     8 

29 

...do 

Aug.  11 

40 

...do 

Aug.  11 

32 

...do 

Aug.  14 

43 

July   11 

July   28 

a  17 

July     4 

July   31 

27 

...do 

Aug.     3 

23 

...do 

Aug.     1 

28 

...do 

Aug.     5 

25 

...do 

Aug.     2 

29 

...do 

Aug.     8 

28 

...do 

Aug.     3 

30 

...do 

Aug.     9 

29 

...do 

Aug.     5 

32 

...do 

Aug.  11 

31 

...do 

Aug.     9 

36 

...do 

Aug.  14 

34 

...do 

Aug.  11 

38 

...do 

Aug.  15 

35 

...do 

Aug.  21 

48 

...do 

Aug.  16 

36 

July     6 

Aug.     2 

27 

...do 

Aug.  18 

38 

...do.... 

Aug.     3 

28 

July    12 

Aug.     6 

25 

...do 

Aug.     4 

29 

...do 

Aug.     8 

27 

...do 

Aug.     5 

30 

...do 

Aug.  15 

34 

...do 

Aug.     8 

31 

...do 

Aug.  17 

36 

...do 

Aug.     9 

34 

...do 

Aug.     2 

21 

...do 

Aug.  10 

35 

...do 

Aug.  10 

29 

...do 

Aug.  21 

46 

...do 

Aug.  14 

33 

...do 

Aug.  22 

47 

...do 

Aug.  20 

39 

...do 

Aug.  30 

55 

July   13 

July   27 

a  14  | 

July     8 

July   25 

ol7 

...do 

July     6 

24 

...do 

Aug.     2 

25 

...do 

July     7 

25 

...do 

Aug.     3 

26 

...do 

July     8 

26 

Date- 


Hatched. 


July   13 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

July  15 
...do 

do 

do 

do 

...do 

...do 

...do 

...do 

...do 

...do 

1    ...do 

1  ...do 

2  July   17 

2  I. ..do 

3  ...do 


1 

!  : 


...do 

...do 

July   19 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

...do 

July   21 

...do 

...do 

...do 


Left 
fruit. 


Aug.  9 
Aug.  10 
Aug.  13 
Aug.  14 
Aug.  16 
Aug.  17 
Aug.  12 
Aug.  15 
Aug.  17 
Aug.  20 
Aug.  12 
Aug.  13 
Aug.  15 
Aug.  16 
Aug.  13 
Aug.  14 
Aug.  15 
Aug.  16 
Aug.  17 
Aug.  18 
Aug.  21 
Aug.  22 
Aug.  27 
Aug.  14 
Aug.  15 
Aug.  16 
Aug.  21 
Aug.  26 
Aug.  12 
Aug.  14 
Aug.  15 
Aug.  16 
Aug.  21 
Aug.  22 
Aug.  24 
Aug.  26 
Aug.  27 
Aug.  16 
Aug.  20 
Aug.  23 
Aug.  20 


a  Probably  previously  infested  apple. 


Summaries  as  to  length  of  feeding  for  both  transforming  and  win- 
tering larva?  are  shown  comparatively  in  Tables  XV  and  XVI. 


CODLING   MOTH   IX    NORTH  WESTERN    PENNSYLVANIA. 


83 


Table  XV. — Larvae  of  the  first  brood.     Comparison  of  the  feeding  periods  of  transforming 
and  wintering  larvae.    Summary  of  Tables  XIV and  XXII. 


Transforming  larvae. 

Wintering  larvae. 

' 

Davs  for 

Davs  for 

Number 

Davs  per 

total 

Number 

Davs  per 

total 

of  larvae. 

larva. 

number 
of  larvae. 

of  larvae. 

larva. 

number 
of  larvae. 

1 

<*14 

14 

1 

ol4 

14 

15 
16 
17 

S 

a  16 
17 
19 

16 

34 

19 

2 

34 

1 

18 

18 

1 

21 

21 

19 
20 
21 

1 
3 
10 

23 

24 

25 

23 

74 

250 

6 

22 

132 

9 

26 

234 

3 

23 

69 

10 

27 

270 

3 

24 

72 

23 

28 

644 

5 

25 

125 

20 

29 

580 

3 

26 

78 

15 

30 

450 

7 

27 

189 

17 

31 

527 

5 

28 

140 

10 

32 

320 

5 

29 

145 

16 

33 

528 

3 

30 

90 

13 

34 

442 

4 

31 

124 

8 

35 

280 

2 

32 

64 

- 

36 

252 

2 

33 

66 

4 

37 

148 

34 
35 

5 
2 

38 
39 

190 
78 

36 

3 

40 

120 

1 

37 

37 

2 

42 

82 

2 

1 
2 

1 

43 
46 
47 
48 

86 
46 
94 
48 



1 

50 

50 

1 

55 

55 

53 

1,397 

192 

5,975 

a  Probably  from  infested  apple. 

Table  XVI . — Larvae  of  the  first  brood.     Comparison  of  the  feeding  periods  of  transforming 
and  wintering  larvae.     Summary  of  Table  XV. 


Observations. 

Days  of  feeding  of— 

Trans-      Winter- 
forming         ing 
larvae.        larvae. 

Average 

Maximum 

Nfinimnm 

26. 36          31. 10 

37                55 
17                17 

84 


DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 


Table  XVII. — Larvx  of  the  first  brood.     Percentage  of  transforming  and  wintering 

larvm  of  cage  material. 


Cage  No. 

Number  of  larvae. 

Cage  No. 

Number  of  larvae. 

Trans- 
forming. 

Winter- 
ing. 

Total. 

Trans- 
forming. 

Winter- 
ing. 

Total. 

2.'.'.'.'.'.'.. 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

11 
4 
9 
9 

14 
9 
2 
5 
7 
5 
2 
2 

7 
3 
8 
6 
13 
27 
17 
14 
6 
11 
5 
4 

18 

7 

17 

15 

27 

36 

19 

19 

13 

16 

7 

6 

13 

14 

5 

17 
6 
7 

12 
9 

19 
8 

22 
6 
7 

12 

e 

19 
9 

15 

16 

17 

18 

19 

Total.. 
Percent.. 

1 

85 

199 

284 

29.93 

70.07 

100.00 

Time  of  maturity  of  transforming  larvx. — From  apples  collected  in  an 
orchard  July  8  the  first  larvae  emerged  July  10,  while  from  banded 
trees  larvae  were  obtained  three  days  later.  In  the  rearing  cages 
the  last  transforming  larva  left  the  fruit  August  14.  (See  Tables 
XXII  and  XXXIII,  and  ^g.  22.) 

Time  of  maturity  of  wintering  larvx. — Of  the  band  record  material  of 
1909  two  larvae,  which  had  been  collected  July  19,  did  not  transform 
with  the  rest  of  the  brood,  but  remained  in  the  larval  stage  and 
wintered.  The  second-brood  larvae  first  appear  about  September  10. 
(See  fig.  22.)  On  examining  the  results  of  the  band  records,  as  pre- 
sented in  figure  21,  it  wrill  be  noted  that  the  greater  number  of  larvae 
belonged  to  the  first  brood,  and  that  the  period  of  maturation  of 
these  larvae  extended  from  early  July  to  the  close  of  September,  or 
perhaps  even  to  the  early  part  of  October. 

Percentages  of  transforming  and  of  wintering  larvx  of  the  first  brood. — 
In  Table  XVII  is  given  a  summary  of  breeding  experiments,  showing 
the  comparative  number  of  transforming  and  wintering  larvae  of  the 
first  brood.  From  these  observations  it  will  be  found  that  in  number 
the  wintering  larvae  exceeded  the  transforming  larvae  about  two  and 
one-half  times.  These  results  agree  closely  with  those  obtained  from 
the  band  material,  which  is  a  better  test  of  the  relative  occurrence 
of  larvae  in  the  field.  (See  Table  XXXIV.)  Of  the  first  brood  23.46 
per  cent  of  the  larvae  transformed  and  76.54  per  cent  wintered. 
Considering  the  two  parallel  records  of  both  cage-reared  larvae,  the 
firsl  brood  consisted  thus  of  one-third  of  transforming  larvae  and 
two-thirds  of  wintering  larva1. 


CODLING   MOTH  IX   NORTHWESTERN   PENNSYLVANIA.  85 

Larval  life  in  the  cocoon. — Cage  records  were  kept  relative  to  the 
time  of  leaving  the  fruit  and  the  time  of  pupation  of  52  individual 
larvae.  This  period  includes  the  time  for  the  making  of  the  cell  and 
the  so-called  post-larval  stage,  which  consists  of  an  inactive  period 
of  one  or  two  days,  when  the  larva  undergoes  structural  changes 
previous  to  pupation.  A  definite  time  limit  for  the  post-larval  stage 
can  hardly  be  given,  since  this  is  a  gradual  change,  which  leads  up  to 
pupation.  In  Table  XXII  the  larval  life  of  the  cocoon  has  been 
referred  to  under  the  making  of  the  cocoon,  as  this  constitutes  the 
main  activity  of  the  larva  during  this  period,  but  it  also  included 
the  post-larval  stage.  The  summary  of  the  larval  life  in  the  cocoon,  as 
recorded  in  Table  XXIII,  agrees  in  a  striking  manner  with  the 
records  obtained  by  Mr.  E.  L.  Jenne  a  in  Arkansas  in  1908.  For 
Xorth  East,  Pa.,  the  average  was  7.09  days,  the  maximum  19  days, 
and  the  minimum  3  days.  Mr.  Jenne's  records  show  an  average  of 
7.2  days,  maximum  19  days,  and  minimum  3  days.  In  instances 
where  the  entire  period  previous  to  pupation  has  been  recorded  to 
last  only  three  days,  it  is  very  probable  that  the  larva?,  when  dis- 
turbed in  the  process  of  making  the  cocoons,  abandoned  the  first 
cocoons  and  made  new  ones.  The  period,  therefore,  appears  shorter, 
as  no  record  was  kept  of  the  time  required  in  making  the  first  cocoon. 

FIRST-BROOD   PUP.E. 

Time  of  pupation. — From  infested  apples,  collected  in  an  orchard 
July  8,  mature  larva?  emerged  July  10  which  pupated  July  16.  From 
the  band  material  pupa?  were  obtained  a  few  days  later  and  were 
observed  in  abundance  throughout  the  period.  The  last  pupation 
occurred  in  the  cages  August  27.  These  late-appearing  pupa?,  how- 
ever, failed  to  develop,  moths  emerging  only  from  larva?  that  pupated 
not  later  than  August  19. 

Length  of  first-brood  pupal  stage. — Of  95  pupa?  of  the  first  brood, 
the  average  duration  of  the  stage  was  12.5  days,  ranging  from  6  to 
22  days.  (See  Table  XX.)  The  records  for  the  individual  pupa? 
are  given  in  Table  XVIII,  with  a  summary  in  Table  XIX,  showing 
variations  observed  in  the  length  of  the  stages  during  the  entire 
period  when  pupa?  were  found.  . 

a  U.  S.  Dept.  Agr.,  Bur.  Ent.,  Bui.  80,  Part  I. 


86 


DECIDUOUS  FRUIT  INSECTS   AND   INSECTICIDES. 


Table  XVIII. — Pupse  of  the  first  brood.     Length  of  the  pupal  periods,  from  material 
collected  in  1909,  on  banded  trees. 


No. 


Date  of- 


Pupa- 
tion. 


July 

July 
...do. 
...do. 

July 
...do. 

July 

July 
...do. 
...do. 
...do. 
...do. 

July 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 

July 

July 
...do. 
...do. 

July 
...do. 

July 

30  ...do. 

31  ...do. 

32  July 


Emer- 
gence. 


23 


28 


Aug. 
Aug. 
Aug. 
...|  Aug. 

19  Aug. 
. ..    Aug. 

20  Aug. 
82     A.m. 

|  Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 
...do. . . 
...do... 
...do... 
...do... 

Aug.     6 

Aug.     5 

Aug.     4 

Aug.  6 
...do. . . 

Aug.  7 
...do.. . 
...do... 
...do... 

Aug.  8 
...do. . . 

Aug.    9 

Aug.     8 


Days. 


No. 


Date  of— 


Pupa- 
tion. 


July  28 
July  29 
..do. .. 
..do... 
July  30 
..do. . . 
..do... 
..do... 
July  31 
..do. . . 
..do... 
..do... 
Aug.     2 

..do 

..do... 
Aug.    3 

..do 

..do. 
..do. 
..do. 
..do. 
..do. 
..do. 
..do. 
..do. 
..do. 
Aug. 
..do. 
..do. 
..do. 
Aug. 
..do. 


Emer- 
gence. 


Aug.  7 
Aug.  8 
Aug.  7 
Aug.     9 

...do 

...do.... 
Aug.  11 
Aug.  12 
Aug.  14 

...do 

Aug.  13 
Aug.  11 
Aug.    9 

...do 

Aug.  8 
Aug.  11 
Aug.  10 

...do 

...do.... 
Aug.  12 
Aug.  13 
Aug.  14 

...do 

Aug.  12 
Aug.  11 
Aug.  13 
Aug.  17 
Aug.  18 

...do 

Aug.  15 
Aug.  28 
Aug.  20 


Days 


10 
10 
9 
11 
10 
10 

12 

13 

14 
14 
13 

11 
7 
7 
6 
8 
7 
7 
7 
9 
10 
11 
11 
0 

8 
10 
12 
13 
13 
10 
22 
14 


No. 


Date  of— 


Pupa- 
tion. 


Aug. 
Aug. 
..do. 
...do. 
..do. 
..do. 
..do. 
Aug. 
Aug. 
Aug. 
...do. 
..do. 
...do. 
...do. 
...do. 
..do. 
Aug. 
..do. 
..do. 
..do. 
Aug. 
..do. 
..do. 
..do. 
..do. 
..do. 
Aug. 
Aug. 
..do. 
Aug. 
Aug. 


Emer- 
gence. 


Aug. 

Aug. 

..do. 

Aug. 

..do. 

Aug. 

..do. 

Aug. 

..do. 

Aug. 

Aug. 

..do. 

..do. 

..do. 

..do. 

..do. 

Aug. 

..do. 

Aug. 

Aug. 

Aug. 

..do. 
...do. 

Aug. 

Aug. 
...do. 

Aug. 

Aug. 

Sept. 

Sept. 


Days. 


,185 


Table  XIX. — Pupae  of  the  first  brood.     Variations  of  pupal  periods.     Summary  of 

Table  XVIII. 


Number 

Pupal 
period 
(days). 

Number 

Pupal 
period 

Number 

Pupal 
period 

Number 

Pupal 
period 

of 

of 

of 

of 

pupse. 

pupse. 

(days). 

pupse. 

(days). 

pupse. 

(days). 

1 

6 

7 

10 

21 

13 

7 

16 

5 

7 

7 

11 

14 

14 

1 

18 

2 

8 

14 

12 

11 

15 

1 

22 

3 

9 

Table  XX. — Pupae  of  the  first  brood.     Length  of  pupal  periods.     Summary  of  Table 

XVIII. 


Observations. 

Pupal 

period 
(days). 

18.8 

Maximum 

Minimum 

22 
8 

CODLING  MOTH  IN   NORTHWESTERN  PENNSYLVANIA. 


87 


FIRST-BROOD    MOTHS. 


Time  of  emergence. — On  August  2  the  earliest  first-brood  moths 
emerged  from  band  material  collected  July  13.  As  shown  in  figure 
20  and  Table  XXI,  the  moths  gradually  increased  in  number,  reach- 


Fig.  20.— Emergence  curve  showing  first-brood  moths,  in  1909,  at  North  East,  Pa.    (Original.) 

ing  a  maximum  on  August  26,  at  which  time  moths  suddenly  de- 
creased, emergence  ceasing  altogether  about  September  3. 

Table  XXI. — Emergence  of  moths  of  the  first  brood.     Material  from  banded  trees. 


Date  of 
emergence. 

Number 
of  moths. 

Date  of 
emergence. 

Number 
of  moths. 

'     Date  of 
emergence. 

Number 
of  moths. 

Date  of 

emergence. 

Number 
of  moths. 

Aug.    2 
Aug.    3 
Aug.    4 
Aug.     5 
Aug.     6 
Aug.    7 
Aug.    8 
Aug.    9 
Aug.  10 

4 
8 
4 
8 
3 
7 
5 
7 
3 

Aug.  11 
Aug.  12 
Aug.  13 
Aug.  14 
Aug.  15 
Aug.  16 
Aug.  17 
Aug.  18 
Aug.  19 

7 
7 
10 
13 
14 
7 
5 
6 
10 

Aug.  20 
Aug.  21 
Aug.  22 
Aug.  23 
Aug.  24 
Aug.  25 
Aug.  26 
Aug.  27 

!8 

9 

8    i 
15 

5 
13 
22 
15 

Aug.  28 
Aug.  29 
Aug.  30 
Aug.  31 
Sept.    2 
Sept.    3 

14 
12 
10 
5 

276 

It  is  of  interest  to  note  that  the  rate  of  emergence  of  the  spring- 
brood  moths  is  almost  the  reverse  of  the  rate  of  emergence  of  the 
first-brood  moths.  In  the  spring,  shortly  after  the  appearance  of  the 
first  moths,  the  maximum  is  attained  within  about  a  week,  while  the 
decrease  in  the  number  of  moths  is  more  gradual  and  extends  over  a 
longer  period. 

Oviposition  period. — For  oviposition  records  moths  of  this  brood 
were  confined  in  rearing  jars,  as  has  already  been  described  for  the 
spring  brood  of  moths  (p.  77) .  As  shown  in  Table  XXIV,  the  observa- 
tions include  twenty-six  separate  jars,  in  which  the  number  of  moths 
varied  from  3  to  17  for  each  jar.  In  five  of  the  jars  no  eggs  were 
30490°— Bull.  80—12 7 


88  DECIDUOUS  FRUIT  INSECTS  AND   INSECTICIDES. 

obtained,  while  in  the  rest  eggs  were  deposited  in  greater  or  less 
abundance.  In  the  summary  of  the  oviposition  records  (Table  XXV) 
it  may  be  observed  that  on  an  average  the  moths  first  oviposited  5 
days  after  their  emergence;  in  one  instance  this  period  extended  to 
L3  days;  the  earliest  oviposition  took  place  2  days  after  emergence. 
The  length  of  oviposition  in  the  various  jars  lasted,  on  an  average,  7 
days,  with  a  maximum  of  15  days  and  a  minimum  of  1  day.  From 
the  time  of  emergence  of  the  moth  the  last  oviposition  in  the  various 
jars  took  place,  on  an  average,  the  eleventh  day,  the  longest  time 
being  19  days  and  the  shortest  6  days.  On  comparing  the  oviposition 
records  of  observations  for  the  two  broods  of  moths  (Tables  VIII  and 
XXV)  it  will  be  noted  that  the  records  show  practically  similar  results. 

The  oviposition  period  extended  from  August  6 — the  fifth  day 
after  the  emergence  of  the  first  moth — to  September  22.  Of  the  late 
deposited  eggs  only  those  laid  previous  to  September  12  hatched,  as 
the  prevailing  cold  weather  at  that  time  stopped  further  develop- 
ments. 

Length  of  life  of  individual  male  and  female  moths. — In  the  various 
stock  jars  which  were  used  in  the  oviposition  experiments  records 
were  kept  as  to  the  length  of  life  of  57  male  and  92  female  moths.  As 
has  already  been  described  in  connection  with  the  spring  brood, 
moths  of  the  first  brood  were  similarly  fed  with  brown  sugar  and 
honey  and  received  daily  fresh  apples  and  apple  foliage  for  oviposition. 
Summaries  of  the  results  of  these  observations  are  given  in  Tables 
XXVI  and  XXVII.  The  average  length  of  life  for  the  male  moths 
was  9.79  days,  and  for  the  female  moths  11.47  days. 

LIFE    CYCLE    OF  THE    FIRST   GENERATION. 

In  connection  with  the  various  rearing  experiments  for  the  separate 
stages  of  the  first  generation  a  set  of  experiments  was  conducted, 
carrying  individual  insects  through  a  complete  life  cycle.  The  results 
of  these  observations  (see  Tables  XXII  and  XXIII)  agree  closely 
with  the  sum  total  of  the  averages  of  observations  on  the  separate 
stages. 


CODLIXG   MOTH  EN    NORTHWESTERN   PENNSYLVANIA.  89 

Table  XXII. — Life  cycle  of  the  first  generation,  as  determined  by  rearing  during  1909. 


No. 

of 
ob- 
ser- 
va- 
tion. 


I 

\ 

5 

6 
7 

B 

9 
10 
11 
12 
13 
14 
15 
16 
17 
IS 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 


Date  of- 


Days  for- 


Egg  dep-     Hatch- 
osition.   |      ing. 


Larva 

leaving 
the  fruit. 


June 

...do. 

...do. 

...do. 

...do. 

...do. 

...do. 

...do. 

...do. 

...do. 

June 

...do. 

...do. 

...do. 

June 

...do. 

June 

...do. 

...do. 

...do.. 

June 

..do.. 

June 

..do.. 

..do.. 

..do.. 

..do.. 

..do.. 

..do.. 

June 

June 

..do.. 

..do.. 

..do.. 

..do.. 

Julv 

..do.. 

..do.. 

..do.. 

..do.. 

July 

..do.. 

..do.. 

July 

..do.. 

July 

..do.. 

July 

..do.. 

..do.. 

..do.. 

..do.. 

July 


24 


23  June  30 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 

July  1 
...do.... 

July  2 
...do.... 
...do.... 
...do.... 

July  4 
...do.... 

July  6 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 
...do.... 

July     8 

July  9 
...do.... 
...do.... 
...do.... 
...do.... 

July  10 
...do.... 
...do.... 
...do.... 
...do.... 

July  11 

...do 

...do.... 

July  12 

...do 

...do.... 
...do.... 

July  13 
...do.... 
...do.... 
...do.... 
...do.... 
13     July   21 


Pupa- 
tion. 


Emer- 
gence of 
moth. 


Hatch- 
ing.    ! 


Feed- 
ing. 


July   27 

...do 

...do.... 
...do.... 
Julv  28 
...do..... 

...do 

July   29 

..do 

July  30 
July   22 

...do 

...do 

July  27 
Aug.  1 
Aug.  3 
July   19 

...do 

Aug.  3 
Aug.  8 
Julv  22 
Julv  30 
July  28 
July  29 
Julv   31 


Aug. 
Aug. 
Aug. 
...do. 
Aug. 
Aug. 
Aug. 
Aug. 
Aug. 


Aug 
Aug 
Aug 
Aug 
Aug 
Aug 
Aug 
Aug.    9 

..do 

Aug.  10 
Aug.  1 
..do.... 
Aug.  6 
Aug.  8 
..do.... 
July  25 
Aug.  5 
Aug.  10 
Aug.  5 
Aug.  14 
Aug.  4 
Aug.  6 
Aug.    7 

..do 

Aug.  9 
Aug.  10 
Aug.  13 
..do  ... 


July 
July 

...do. 
July 
Aug. 

...do. 

LJUdo. 
I  Aug. 

Aug. 

July 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

Aug. 

..do. 

Aug. 

Aug. 

Aug. 

Aug. 

i  Aug- 
:  Aug. 

Aug. 
!  Aug. 

Aug. 

Aug. 

July 
■  Aug. 

Aug. 

Aug. 

Aug. 
i  Aug. 

Aug. 

Aug. 

Aug. 
i  Aug. 

Aug. 
j  Aug. 

Aug. 


Aug.  20 
Aug.  18 
Aug.  15 

..do 

Aug.  23 
Aug.  16 
Aug.  17 
Aug.  19 
Aug.  23 
!  Aug.  15 
I  Aug.  9 
Aug.  11 


cocoon.  Penoa- 


.::."&:.:: 


...do.... 

Aug.  20 

Aug.  23 

Aug.  3 

Aug.  5 

Aug.  24 

Aug.  29 

Aug.  9 

Aug.  23 


R 

6 

n 

Aug. 

19 

10 
8 

Aug. 

25 

15" 

8 

Aug. 
Aug. 

19 
28 

11 

26 

14 

16 

9 

16 
97 

Aug. 
Aug. 
Aug. 

31 
23 
30 

IS 
31 
11 

Sept. 
Aug. 

3 
14 

M 

r> 

19 

8 
9 

Aug. 

22 

11 

13 
16 

Aug. 

27 

14 

In 

Aug. 

28 

23 

29 
29 
30 
22 
22 
22 
27 
31 
33 
17 
17 
32 
37 
18 
26 
22 
23 
25 
26 
28 
29 
30 
24 
24 
26 
31 
31 
32 
22 
22 
27 
29 
29 
a  14 
25 
30 
24 
33 
23 
25 
25 
25 
27 
28 
31 
23 


408   1, 397 


Total 

life 
cvcle. 


9 

15 

7 

15 

6 

13 

6 

13 

11 

15 

7 

12 

6 

14 

7 

14 

11 

14 

7 

11 

6 

14 

6 

14 

3 

12 

8 

11 

8    

5 
6    .. 

13 

52 

6 
3    .. 

15 

58 

7 
13 
4    .. 

11 
13 

51 
59 

2    

17    

4    

15 
8 
10 
19    .. 

15 

14 
14 

61 
53 
60 

10 
6 
6    .. 

16 
14 

64 

43 

12    

7    

5    

4 
3    .. 

14 

49 

4    

6 
7    .. 

14 

53 

4 
5    .. 

14 

54 

10    

450  1,824 


a  Probably  from  infested  apple. 
Table  XXIII. — Life  cycle  of  the  first  generation.     Summary  of  Table  XXII. 


Observations. 

Days  for— 

Hatch-  !  Feedin„     Making       Pupal    |    Total 
ing.        x  Cliiu6-   ofcocoon.    period,    life-cycle. 

Average 

Maximum 

Minimum 

7. 7          26. 36            7. 09 
9              37                19 
6              17                 3 

13.63 

16 

11 

53.64 

64 

38 

90 


DECIDUOUS  FRUIT  INSECTS   AND   INSECTICIDES. 


Since  the  life  cycle  is  considered  to  begin  with  the  appearance  of 
the  eggs,  it  becomes  first  completed  with  the  appearance  of  eggs  from 
moths  of  t ho  same  generation.  The  average  period  between  the 
emergence  of  moths  and  first  opposition  must  therefore  be  added  to 
the  life  cycle  and  not,  as  might  be  thought,  the  length  of  life  of  the 
moth  (see  Tables  XXVI  and  XXVII).  The  sum  total  of  the  averages 
for  the  stages  together  with  the  average  of  5  days  for  the  oviposition 
(see  Tables  XXIV  and  XXV)  makes  58.28  days;  the  average  for  the 
life  cycle  of  individuals  reared  through  all  stages  together  with  5  days 
for  oviposition  was  58.68  days. 

Table  XXIV. — Oviposition  periods  of  moths  of  the  first  brood  in  rearing  cages. 


Cage 

No. 

Num- 
ber of 
moths. 

Date  of— 

Days- 

Emer- 
gence of 
moth. 

First 
ovi- 
position. 

Last 
ovi- 
position. 

Before 

ovipo- 
sition. 

Length 

of 
ovipo- 
sition. 

Be- 
tween 
emer- 
gence 
and  last 
ovipo- 
sition. 

1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 

4 
7 
4 
8 
3 
8 
3 
7 
4 
6 
3 
4 
4 
4 
5 
7 

12 

17 

10 

14 

11 

10 

9 

6 

4 

6 

Aug.    2 
Aug.    3 
Aug.    4 
Aug.    5 
Aug.    6 
Aug.    7 
Aug.    8 
Aug.    9 
Aug.  10 
Aug.  11 
Aug.  12 
Aug.  14 
Aug.  15 
Aug.  16 
Aug.  17 
Aug.  18 
Aug.  19 
Aug.  20 
Aug.  21 
Aug.  23 
Aug.  25 
Aug.  27 
Aug.  29 
Aug.  30 
Sept.    3 
Sept.    6 

Aug.    9 
Aug.    6 
Aug.    7 

...do 

Aug.  13 
Aug.    9 

Aug.  12 
Aug.    9 
Aug.  10 
Aug.  20 
Aug.  13 
Aug.  20 

7 
3 
3 

2 

7 
2 

4 
4 
4 

14 
1 

12 

10 
6 
6 

15 
7 

13 

Aug.  13 

Aug.  25 

4 

13 

16 

Aug.  16 
Aug.  25 

Aug.  20 
Aug.  26 

5 
13 

5 
2 

9 
14 

Aug.  19 
Aug.  20 
Aug.  24 
Aug.  22 

...do 

Aug.  25 

...do 

Aug.  21 
Aug.  26 
Aug.  27 
Aug.  28 
Aug.  29 
Aug.  31 
Sept.    9 

4 
4 

7 
4 
3 
5 
4 

3 

7 
4 
7 
8 
7 
15 

6 
10 
10 
10 
10 
11 
19 

Aug.  28 
Aug.  30 
Sept.    2 

Sept.    4 
Sept.  11 
Sept.  12 

3 
3 
5 

8 
13 

11 

10 
15 
14 

Sept.  11 
Sept.  15 

Sept.  15 
Sept.  22 

8 
9 

5 
8 

12 
16 

105 

155 

239 

Table  XXV .— Oviposition  periods  of  moths  of  the  first  brood.    Summary  of 

TabhXXIV. 


Observations. 

Days— 

Before 
first  ovi- 
position. 

Length 
of  ovi- 
position. 

Between 
emergence 
and  last 
oviposi- 
tion. 

5.0 
13 
2 

7.38 
15 
1 

11.38 
19 

6 

Maximum 

Minimum 

CODLING   MOTH  IN   NORTHWESTERN   PENNSYLVANIA. 


91 


Table  XXVI.— Longevity  of  male  and  female  moths  of  the  first  brood.    Summary  of 
records  of  149  individual  moths. 


Male. 

Female. 

Male. 

Female. 

Length 

Number 

Length 

Number 

Length 

Number 

Length 

Number 

of  life. 

of  moths. 

of  life. 

of  moths. 

of  life. 

of  moths. 

of  life. 

ofmoths. 

Days. 

Days. 

Days. 

Days. 

2 

3 

2 

1 

14 

2 

14 

7 

3 

1 

3 

4 

15 

3 

15 

3 

4 

3 

4 

2 

Id 

3 

16 

6 

5 

1 

5 

2 

17 

2 

17 

7 

6 

1 

6 

4 

18 

1 

18 

2 

7 

5 

6 



19 

1 

8 

6 

8 

5 

20 

1 

9 
10 
11 
12 

9 

4 
3 
5 

9 
10 
11 
12 

4 
9 
8 
7 

21 
22 

1 
2 

57 

92 

13 

5 

13 

10 

Table  XXVII. 


-Longevity  of  male  and  female  moths  of  the  first  brood.    Summary  of 
Table  XXVI. 


Observations. 

Life  of 
male 
i   moths. 

Life  of 

female 
moths. 

Average 

Maxim  um 

Minimum 

1    Days. 
9.79 

...         IS 
...'          2 

Days. 
11.47 
22 
2 

On  further  testing  the  rearing  results  by  taking  the  dates  of  the 
maximum  emergence  of  the  spring  brood  of  moths  (June  24)  and  the 
emergence  of  moths  of  the  first  brood  (August  26)  it  will  be  found 
that  63  days  elapsed.  But  since  the  emergence  of  moths  of  the  first 
brood  was  very  gradual,  reaching  its  maximum  first  at  the  close  of 
the  season  (fig.  22),  it  becomes  evident  that  the  average  of  58.5  days 
is  fairly  accurate. 

THE    SECOND    GENERATION. 
SECOND-BROOD    EGGS. 

Incubation  period. — From  two  to  three  days  after  egg  deposition, 
a  semicircular  red  ring  appears  within  the  egg,  which  later  disappears 
as  the  embryo  attains  further  growth.  Commonly  this  condition  of 
the  egg  is  referred  to  as  the  "red-ring"  stage.  A  black  spot  ap- 
pears in  the  egg  from  two  to  three  days  previous  to  hatching,  and  is 
caused  by  the  dark-colored  portions  of  the  head  and  prothorax  of 
the  future  larva  which  are  partly  visible  through  the  eggshell.  In 
taking  observations  on  these  features  of  incubation  no  fixed  time  can 
be  given,  as  these  changes  set  in  and  disappear  gradually  with  the 
growth  of  the  embryo  or  young  larva.  It  is  of  value  to  know  the 
significance  of  the  "red  ring"  and  the  " black  spot,"  as  the  age  of 
the  eggs  can  thus  be  approximately  determined  in  the  field. 

In  the  cages  eggs  were  laid  daily  during  the  entire  egg-deposition 
period,  which  extended  from  August  6  to  September  22,  and  a  full 
record  of  the  incubation  period  was  kept  during  this  time  (Table 
XXVIII). 


92  DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 

Table  XXVIII. — Second-brood  eggs.     Incubation  periods  of  eggs  laid  in  rearing  cages. 


No.  of 

obser- 
vation. 


40 
41 
42 
43 
44 
4f) 
46 
47 
48 

4'.) 

GO 
51 
62 
63 
64 

:>-> 

66 

,r)7 

58    . 

59 

BO 

61 

83 

63 

64 

66 

66 

67 


Date. 


Depos- 
ited. 


Aug.  6 
A  u«.  7 
Aug.  8 
Aug.     9 

...do 

Aug.  10 

..do 

Aug.  11 
Aug.  12 

..do 

Aug.  13 
..do 

...do.... 

...do.... 
..do.... 
Aug.  14 

...do 

...do.... 
..do.... 
Aug.  15 
Aug.  16 
Aug.  17 
Aug.  18 

..do 

Aug.  19 

..do 

Aug.  20 

..do 

Aug.  21 
Aug.  22 

..do 

Aug.  23 
Aug.  24 

..do 

Aug.  25 

..do 

Aug.  26 

..do 

..do.... 
Aug.  27 

..do 

Aug.  28 

..do 

..do.... 
Aug.  29 

..do 

..do.... 
..do.... 
Aug.  30 

...do 

Aug.  31 

...do 

...do.... 

.«..*. 

Sept. 


Red 

ring. 


T. 


Sept.  4 

Sept.  5 

Sept  0 

Sept.  7 

Sept."   8" 

..do 

...do.... 
Sept.    9 

.'.'.do'.'.'.'. 
Bept  in 
Sept.  11 

'.'.'.<lo~. '.'.'. 
Sept.  12 
Bept  15 
Bept  is 

Bept  a 


Aug. 
Aug. 
Aug. 

..do. 
..do. 
Aug. 
..do. 
Aug. 
Aug. 
..do. 
..do. 
..do. 
..do. 
Aug. 
..do. 
Aug. 
Aug. 
..do. 
..do. 
Aug. 
Aug. 
Aug. 
Aug. 
..do. 
..do. 
Aug. 
Aug. 
...do. 


12 


16 


Black 
spot. 


Aug. 
...do 
Aug. 


Aug 
...do 
...do 
...do 
...do 

Aug. 
...do 

Aug. 
...do 

Aug. 
...do 
...do 
...do 

Sept. 

*£ 

...do 
...do 
...do 
Sept. 

Sept. 

!"do 
Sept. 
Sept. 

*£ 

...do 

.*£ 

...do 

*C 

...do 

*% 

.  ..do 
do 


Aug.  11 
Aug.  13 
Aug.  14 
Aug.  15 

...do 

Aug.  16 

...do 

Aug.  18 

...do 

...do.... 
Aug.  19 

...do 

...do.... 
...do.... 
Aug.  20 

...do 

...do.... 

do.... 

...    Aug.  21 

17  Aug.  22 

18  Aug.  24 

19  ...do 

21  I  Aug.  25 

do 

do.... 

22  ...do.... 

23  Aug.  27 

do 

...    Aug.  28 

24  ...do.... 
do.... 

25  Aug.  29 
do 

Aug.  30 
Aug.  31 

..do 

..do.... 
..do.... 
Sept.    1 


.  27 


29 


30  Sept.    8 
...  ...do... 

31  J  Sept.    9 

".'.'.  ^!do"; 

...    Sept.  10 
1    ...do... 

3  J  Sept.  11 
...  ...do... 

do... 

. . .   Sept.  12 
do. .. 

4  ...do... 
do... 

5  I  Sept.  13 

'.'.'.  ...do'.'.'. 

3ept  14 

8  ...do... 
..do... 
..do... 
..do... 
Sept.  15 

Bept*  16 

'.'.do'.'.'. 
Bept  i: 
Bept  16 

st-': 

Sept.   is 

Bept  r> 


10 


n 


12 


Hatched 


Aug. 
Aug. 
Aug. 
Aug. 
Aug. 
..do 
Aug. 
Aug.  . 

...do 

Aug.  20 
Aug.  19 
Aug.  20 
Aug.  21 
Aug.  22 
Aug.  23 
Aug.  21 
Aug.  22 
Aug.  23 
Aug.  24 

..  do 

Aug.  25 

...do 

Aug.  26 
Aug.  27 
Aug.  26 
Aug.  27 
Aug.  28 
Aug.  29 
...do  ... 
...do... 
Aug.  30 
Aug.  31 
Sept. 
Sept. 
Sept. 
Sept. 
Sept. 
Sept. 
Sept. 
Sept. 
Sept. 
Sept.  . 
Sept.  10 
Sept.  11 

...do 

Sept.  12 
Sept.  13 
Sept.  14 
Sept.  12 
Sept.  13 

...do 

Sept.  14 
Sept.  15 
Sept.  13 
Sept.  14 

'.'.'.do'.'.'. 
Sept.  15 

'.'.'.do'.'.'. 
...do... 
...do... 

Sept.  16 

Sept  17 
Bept  is 
Sept.  17 
Bept  is 
Bept  10 
Bept  17 
Bept  is 
Bept  19 
Bept  20 


Days. 


Red 

ring. 


Black 

spot. 


Incu- 
bation. 


10 


CODLING   MOTH  IN   NORTHWESTERN   PENNSYLVANIA. 


93 


The  incubation  period  ranged  from  6  to  16  days,  with  an  average 
of  9.47.  In  the  time  of  appearance  of  the  red  ring,  the  range  varied 
from  1  to  4  days,  with  an  average  of  2.4  days.  The  black  spot 
appeared  on  an  average  7.66  days  after  egg  deposition,  and  hatching 
generally  took  place  from  1  to  2  days  after  the  black  spot  had  been 
observed.     (Tables  XXIX  and  XXX.) 

Table  XXIX. — Incubation  periods  of  second-brood  eggs.    Summary  of  Table  XX  VIII. 


Appearance  of  red 
ring. 

Appearance  of 
black  spot. 

Total  incubation 
period. 

Number 

Number 

Number 

Number 

of 

Number 

of 

Number 

of 

of  days. 

observa- 

of days. 

observa- 

of days. 

observa- 

tions. 

tions. 

tions. 

1 

6 

5 

4 

6 

1 

2 

32 

6 

26 

7 

12 

3 

30 

7 

19 

8 

20 

4 

3 

8 

4 

9 

16 

9 

1 

10 

7 

10 

3 

11 

2 

11 

8 

12 

4 

12 

7 

13 
14 
15 
16 

5 
4 
2 

1 

Table  XXX. 


■Incubation  periods  of  second-brood  eggs.    Summary  of  Tables  XXVIII 
and  XXIX. 


Observations. 

Number  of  days— 

For  appear- 
ance of 
red  ring. 

For  appear- 
ance of 
black  spot. 

For  incu- 
bation. 

2.4 
4 

1 

7.66 
12 
5 

9.47 
16 

6 

Maximum 

Minimum 

Eggs  deposited  from  September  15  to  September  22,  inclusive, 
failed  to  hatch  because  of  prevailing  cold  weather. 


SECOND-BROOD   LARVAE. 


Time  of  hatching. — The  extent  of  the  hatching  period  of  second- 
brood  larvae  can  be  accurately  determined,  since  eggs  were  obtained 
August  6  from  the  earliest  emerging  moths  and  subsequently  almost 
daily  until  September  22.  In  the  cages  the  first  larvae  hatched 
August  13  and  the  last  September  21;  late-deposited  eggs,  as  already 
stated,  failed  to  develop  because  of  cold  weather,  which  limited  the 
number  of  the  second-brood  larvae  considerably. 

Feeding  period. — From  a  number  of  larvae  that  hatched  in  the 
cages,  100,  as  given  in  Table  XXXI,  developed  about  normally  and 
entered  hibernation. 


94  DECIDUOUS  FRUIT  INSECTS  AND   INSECTICIDES. 

Table  XXXI. — Larrx  of  second  brood.     Periods  of  feeding  of  larvae  in  rearing  cages. 


No.  of 

larva'. 


Date  of- 


Hatch- 
ing. 


Aug. 

..do. 
...do. 

Aug. 
...do. 
...do. 
...do. 

Aug. 
0    ...do. 


13 


do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 

Aug. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 
...do. 

Aug. 
...do. 
...do. 

Aug. 
...do. 
...do. 


L6 


Lew  Ins 

tin-  fruit. 


Sept  n 


17 


19 


*&. 
*&. 
*&. 

..do. 
Sept. 
Sept. 

5ft 

..do. 

s%. 

Sept. 
Sept. 
Oct. 
Oct. 
Sept. 
Sept. 

'ft. 

..do. 
Sept. 
Sept. 

SX. 

Sept. 
Sept. 
Sept. 
Sept. 

.!£ 

Sept. 


Sept.  12 


Sept.  18 


Date  of— 

T 

No.  of 
lar- 
vae. 

Davs 

feed- 
ing. 

Hatch- 
ing. 

Leaving 

the  fruit. 

feed- 
ing. 

29 

36 

Aug.  19 

Sept.  29 

41 

29 

37 

...do.... 

Oct.     8 

50 

30 

38 

...do.... 

Oct.    22 

64 

29 

39 

...do.... 

...do.... 

64 

34 

40 

Aug.  20 

Oct.     3 

44 

34 

41 

...do.... 

Oct.    10 

51 

34 

42 

Aug.  21 

Sept.  19 

29 

28 

43 

...do.... 

29 

29 

44 

...do.... 

Sept.  20 

30 

32 

45 

...do.... 

30 

32 

46 

...do.... 

Sept.  23 

33 

32 

47 

...do.... 

Oct.     9 

49 

33 

48 

...do.... 

Oct.    26 

66 

33 

49 

Aug.  22 

Sept.  17 

26 

37 

50 

...do.... 

Sept.  19 

28 

40 

51 

...do.... 

Sept.  28 

37 

48 

52 

...do.... 

Sept.  29 

38 

54 

53 

Aug.  24 

Oct.     1 

40 

30 

54 

...do.... 

Sept.  28 

35 

32 

55 

...do.... 

Oct.      9 

46 

32 

56 

...do.... 

Oct.    23 

60 

33 

57 

Aug.  25 

Sept.  22 

28 

33 

58 

...do.... 

28 

33 

59 

...do.... 

Sept.  28 

28 

34 

60 

...do.... 

28 

38 

61 

...do.... 

Sept.  21 

27 

41 

62 

...do.... 

Sept.  28 

34 

41 

63 

...do.... 

Oct.     1 

37 

44 

64 

...do.... 

Nov.    1 

60 

30 

65 

Aug.  26 

Sept.  26 

31 

32 

66 

...do.... 

Oct.     8 

43 

36 

67 

...do.... 

Oct.      9 

44 

29 

68 

...do.... 

Oct.    11 

46 

29 

69 

...do.... 

...do.... 

46 

31 

70 

Aug.  27 

Oct.     4 

38 

No.  of 
lar- 
va'. 


Date  of- 


Hatch-     Leaving 
ing.        the  fruit. 


Aug. 
...do. 
...do. 
...do. 

Aug. 
...do. 

Aug. 
...do. 

Aug. 

Aug. 
...do. 
...do. 
...do. 

84  Sept. 

85  ...do. 

86  ...do. 

87  ...do. 
8S     Sept. 

89  ...do. 

90  |...do. 

91  ...do. 

92  ...do. 

93  ...do. 

94  ,  Sept. 

95  [...do. 
..do. 
..do. 

98  I. ..do. 

99  ...do. 

100  Sept. 

101  Sept. 


<>: 


27  Oct.  4 
...  Oct.  7 
...  Oct.  8 
.  .  .     Nov.     1 

28  Oct.  4 
. .  .    Oct.    10 

29  ...do... 
. .  .    Nov.     1 

30  Oct.      9 

31  Sept.  26 
. ..  Oct.  7 
...  Oct.  8 
. ..    Oct.    26 

2  Oct.  5 
. ..  Oct.  11 
. ..  Nov.  2 
. .  .    Nov.  12 

3  Oct.  1 
...  Nov.  2 
do... 

. .  .    Nov.     4 

...    Nov.    8 

Oct.    15 

Sept.  29 

Oct.     3 

Oct.     9 

Oct.    12 

Oct.    15 

Nov.  13 

5     Oct.    26 

10     Nov.  15 


Davs 

feed- 
ing. 


41 
42 
66 
37 
43 
42 
64 
40 

a26 
37 
38 
56 
33 
39 
61 
71 

a28 
60 
60 
62 
66 
73 

a25 
29 
35 
38 
41 
70 
51 


1,254 


a  Probably  from  infested  apple. 

Table  XXXII. — Feeding  periods  of  larvae  of  the  second  brood.    Summary  of  Table 

XXXI. 


Observations. 


Average.. 
Maximum 
Minimum . 


Feeding 
periods. 


Days. 
39.5 
73 
26 


CODLING   MOTH  IN    NORTHWESTERN   PENNSYLVANIA.  95 

The  feeding  periods  for  these  larvae  ranged  from  26  to  73  days, 
with  an  average  of  39.5  days.  The  feeding  periods  in  the  above 
records  are  strikingly  longer  than  those  obtained  for  larva?  of  the 
first  brood.  This  is  probably  due  to  lower  temperature,  which 
during  the  middle  of  October  for  7  days  brought  the  activities  of 
insects  to  an  apparent  standstill. 

Time  of  leaving  the  fruit  for  wintering. — In  the  cages,  the  first  larvae 
left  the  fruit  September  11,  and  since  these  were  from  the  earliest 
eggs  of  the  first  moths,  these  records  must  be  approximately  accurate. 
The  length  of  feeding  for  the  early  larvae  of  the  second  brood  was  29 
to  30  days;  the  larvae  hatched  August  13,  wintering  September  11. 
With  these  established  facts  it  is  thus  possible  to  separate  the  first- 
brood  and  second-brood  larvae  from  the  banded  trees,  which  as  to 
time  of  reaching  maturity  overlapped  considerably.  (See  fig.  21.) 
In  the  fall,  during  the  alternating  warm  and  cold  days,  larvae  appeared 
under  the  bands  in  variable  numbers,  as  recorded  in  Table  XXXIII. 
The  bands  were  last  examined  November  13,  when  9  larvae  were  col- 
lected.    In  the  rearing  cages  the  last  larvae  emerged  November  15. 

Immature  larvx  at  hibernation  time. — It  is  evident  from  both  field 
and  rearing  observations  that  during  the  latter  part  of  November, 
when  the  temperature  had  already  reached  20°  F.,  quite  a  number 
of  larvae  had  not  yet  attained  maturity.  Of  the  reared  larvae  that 
hatched  September  12  several  which  were  only  one-third  to  one-half 
grown  remained  in  the  fruit,  while  others  hatching  September  21  were 
only  one-fifth  to  one-sixth  grown. 

From  the  bands  several  undersized  larvae  were  collected  late  in  the 
fall,  and  it  will  be  of  interest  to  know  whether  or  not  they  are  in  con- 
dition to  transform  the  coming  spring.  With  the  records  in  hand  it 
is  not  possible  to  give  the  relative  number  of  immature  larvae  in  the 
field  that  failed  to  enter  hibernation  places.  In  the  cages,  of  133 
reared  larvae  32  remained  in  the  fruit  in  the  fall,  and  judging  from 
their  size  it  is  doubtful  if  any  of  them  could  possibly  attain  maturity 
that  late  in  the  season. 

BAND   RECORDS    OF    1909. 

Through  the  courtesy  of  Mr.  C.  E.  Luke,  of  North  East,  Pa.,  an 
apple  orchard  of  50  trees  was  obtained,  which  was  particularly  well 
suited  for  band  records.  The  trees  were  about  25  years  old  and, 
to  the  owner's  knowledge,  had  never  been  sprayed  and  for  some  time 
past  had  received  no  care.  For  several  years  no  fruit  had  been  gath- 
ered from  the  orchard.  It  is  thus  evident  that  for  vears  the  codling 
moth  had  developed  without  interference  and  existed  under  natural 
conditions.     In  1909  most  of  the  trees  carried  a  heavy  crop  of  fruit. 


96 


DECIDUOUS   FRUIT  INSECTS  AND  INSECTICIDES. 


After  the  loose  bark  had  been  scraped  from  the  trunks  of  16  trees, 
burlap  bands  were  placed  around  the  main  trunk  in  the  usual  man- 
ner about  3  feet  from  the  ground.  On  5  of  the  trees  bands  were  also 
placed  on  t  he  main  branches,  so  as  to  obtain  records  as  to  the  relative 
number  of  larvae  ascending  the  trees  from  the  ground  from  wind-fallen 
fruit,  as  compared  with  the  number  of  larvae  descending  from  fruit 
on  the  trees.  The  trees,  with  one  exception,  consisted  of  winter  varie- 
ties, 10  of  which  were  Golden  Russet,  1  Northern  Spy,  2  Greening, 
and  3  undetermined.  Since  only  16  trees  of  the  whole  orchard  were 
banded,  it  is  believed  that  the  comparatively  small  number  of  first- 


Fio.  21.— Band-record  curve  of  1909,  at  North  East,  Pa.    (Original.) 

brood  larvae  which  were  removed  had  no  influence  upon  the  number 
of  larvae  of  the  second  brood.  With  the  appearance  of  the  first  larvae, 
July  13,  the  banded  trees  were  examined  every  three  days  throughout 
the  season  until  November  13.     (See  fig.  21.) 

In  comparing  the  number  of  larvae  collected  from  the  upper  and 
the  lower  bands,  it  will  be  noted  (Table  XXXIII)  that  53  per  cent 
were  taken  from  the  lower  bands  and  47  per  cent  from  the  upper 
bands.  These  figures  are  of  interest  as  bearing  on  the  effectiveness 
of  gathering  windfalls.  A  summary  of  the  band  records  is  given  in 
Table  XXXIV. 


CODLING   MOTH  IX    NORTHWESTERN   PENNSYLVANIA.  97 

Table  XXXIII.—  Records  of  larvae  collected  from  banded  trees  during  1909. 


No.  of 
record. 

Date  of 
collect- 
ing. 

Number  of  larvae. 

Dead  or 
parasit- 
ized. 

Number 
of  trans- 
forming 
larvae 
(1909). 

Number 
of  win- 
tering 
larvae. 

Upper       Lower 

bands        bands 

(5  trees).    (5  trees). 

Total 
(16  trees). 

l 
2 
«      3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
•  40 
41 
42 

July  13 
July   16 
Julv   19 
July  22 
July  25 
Julv  28 
Julv  31 
Aug.    3 
Aug. 
Aug.    9 
Aug.  12 
Aug.  15 
Aug.  IS 
Aug.  21 
Aug.  24 
Aug.  27 
Aug.  30 
Sept.    2 
Sept.    5 
Sept.    8 
Sept.  11 
Sept.  14 
Sept.  17 
Sept.  20 
Sept.  23 
Sept.  26 
S«>pt.  29 
Oct.      2 
Oct.      5 
Oct.     8 
Oct.    11 
Oct.    14 
Oct.    17 
Oct.    20 
Oct.    23 
Oct.    26 
Oct.    29 
Nov.    1 
Nov.     4 
Nov.    7 
Nov.  10 
Nov.  13 

13 

6                  7 

3  2 

4  5 
6                   2 

29 
19 
21 
24 
54 
48 
74 
68 
77 
97 
79 
68 

11                 18 

1 

2 
2 

16 
20 
18 
30 
23 
51 
30 
40 
45 
3 

2 

8 
11 
10 
22 
24 
23 
23 
15 

3 

7 
14 
17 
10 
15 
22 
18 

5 

22 
23 
23 
32 
37 
52 
76 
68 
88 
83 
99 
94 
56 
64 
38 

13                19 

8  30 

13  19 
18    |            26 

14  24 

5  11 

6  15 

7  10 
7                  9 

9  7 
3 

88 
83 
100 
94 
56 
64 
38 
47 



1 









47 

53 
37 

53 

37 

4 

8 
3 
2 
4 

5 

7 
9 

1 

5                21 
10                46 
4                20 

2  13 

3  13 
3                 15 

21 

46 

20 

13 



13 

15 

6 
12 

1 

29 

44 

5 

29 
44 
5 

1 
5 
2 
3 
6 
9 

1 

1 
2 
8 
3 
1 
3 
5 

4 

16 

6 

17 

26 

14 

2 

6 

9 

4 

16 

6 

17 
26 

14 

2 

G 

2 

9 

324 

366 

1,631 

25 

801 

1.305 

Table  XXXIV.- 


-Records  of  larvae  collected  from  banded  trees  during  1909. 
of  Table  XXXIII. 


Summary 


Larvae  from  upper  bands 46. 95 

Larvae  from  lower  bands 53. 04 

Transforming  larvae  of  band  collections '  18. 74 

Wintering  larvae  of  band  collections >  81. 26 

Relative  proportion  of  first-brood  larvae S3. 87 

Relative  proportion  of  second-brood  larvae 16. 13 

Transforming  larvae  of  first  brood 23. 46 

Wintering  larvae  of  first  brood i  76. 54 


Few  of  the  results  here  obtained  have  been  based  upon  observa- 
tions made  during  the  rearing  in  the  laboratory.  For  instance,  the 
two  broods  of  larva?,  which  at  the  time  of  maturity  overlap,  could 
only  be  separated  through  rearing  experiments.     On  comparing  the 


98  DECIDUOUS   FRUIT  INSECTS   AND  INSECTICIDES. 

two  broods  of  larvae  it  will  be  noted  that  the  first  brood  exceeded  in 
number  the  second  brood  about  five  times.  Considering  the  number 
of  transforming  larvae  and  the  number  of  wintering  larvae  of  the  first 
brood,  it  was  found  that  only  one-fourth  of  the  brood  completed  the 
life  cycle  the  same  season,  while  three-fourths  of  the  brood  hiber- 
nated, attaining  their  full  development  with  individuals  of  the  second 
brood. 

REVIEW    OF   THE   LIFE-HISTORY   WORK   OF   1909. 

During  1 909  an  attempt  was  made  to  rear  the  codling  moth  through- 
out the  season,  and  to  determine  the  time  and  relative  occurrence  of 
the  different  stages  of  the  two  broods.  The  essential  results  of 
observations  for  the  season  are  shown  in  the  diagram  (fig.  22). 
The  moths  in  the  spring  commenced  to  emerge  June  11,  reaching  a 
maximum  of  emergence  June  24.  Moths  of  the  following  brood — 
the  first-brood  moths — appeared  from  August  2  to  September  3, 
with  a  maximum  August  26.  Oviposition  generally  took  place  the 
fifth  day  after  the  emergence  of  the  moths  of  either  brood.  The 
time  during  which  the  first  brood  larvae  attained  maturity  extended 
from  July  10  to  the  end  of  September.  Only  one-fourth  of  the 
larvae  of  this  brood  transformed  and  completed  the  life  cycle  the 
same  year,  while  three-fourths  of  the  larvae  hibernated.  Of  the 
second  brood,  mature  larvae  appeared  first  on  September  11  and 
continued  to  appear  until  the  middle  of  November,  at  which  time 
quite  a  number  was  prevented  from  further  growth  and  failed  to 
enter  hibernation  places  because  of  prevailing  low  temperature. 
Judging  by  the  number  of  larvae  collected  from  the  banded  trees, 
individuals  of  the  first  generation  exceeded  in  number  the  second 
generation  five  times. 

SEASONAL-HISTORY  STUDIES  OF  1907  AND  1908. 

SOURCE    OF   REARING   MATERIAL. 

The  rearing  material  for  the  spring  of  1907  was  collected  from  a 
cider  bin  May  9,  before  any  larvae  had  transformed.  Later  in  the 
season  larvae  were  obtained  from  banded  apple  trees,  which  were 
then  used  partly  the  same  year  and  partly  (overwintering  larvae)  for 
emergence  records  of  moths  the  following  spring.  Additional  band 
material  was  obtained  in  1908,  which,  together  with  a  small  number 
of  reared  larvae,  constituted  the  entire  supply  used  that  year. 

The  rearing  work  for  the  two  seasons  of  1907  and  1908  was  carried 
out  on  an  openporch  of  the  laboratory  building,  or  out  of  doors  under 
trees  in  the  laboratory  yard,  and  it  is  thus  believed  that  the  records 
of  observations  represent  the  normal  transformation  of  the  insect 
in  orchards. 


CODLING  MOTH  IN   NORTHWESTERN  PENNSYLVANIA. 


99 


k 


£ 


13        /        — 


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rr 


'-£ 


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CO 


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100 


DECIDUOUS   FRUIT  INSECTS  AND   INSECTICIDES. 


TIME   OF   EMERGENCE   OF   MOTHS    OF   THE    SPRING    BROOD. 

The  first  moth  observed  in  1907  appeared  in  the  cages  June  17  and 
t  ho  last  July  10.  The  emergence  period,  as  shown  in  figure  23,  lasted 
twenty-three  days,  reaching  a  maximum  on  June  24.  These  emer- 
gence records  are  given  in  Table  XXXV. 

Table  XXXV. — Emergence  of  spring  moths  during  1907,  from  material  collected  in  a 

cider  bin. 


Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

June  17 
June  18 
June  20 
June  21 
June  22 

1 
1 

2 
3 
6 

June  23 
June  24 
June  25 
June  26 
j    June  27 

14 
27 
14 
15 
3 

June  28 
June  29 
July     1 
July     2 
July     3 

10 
6 
1 
6 
2 

July     5 
July     6 
July    10 

4 
4 
2 

124 

In  the  spring  of  1908  moths  commenced  to  appear  in  the  cages  by- 
May  30.  The  last  moth  of  this  brood  emerged  June  24.  Unfortu- 
nately no  record  as  to  the  number  of  emerging  moths  was  kept,  and 
their  relative  abundance  can  thus  only  be  estimated.  Judging  by  the 
size  of  a  number  of  larvae  collected  in  an  orchard  June  10,  it  was  evi- 
dent that  moths  in  the  field  must  have  appeared  even  earlier  than 
those  emerging  in  the  cages  and,  on  considering  the  band  records  also, 
it  is  probable  that  the  emergence  extended  to  the  end  of  June. 

TIME    OF   EMERGENCE   OF   MOTHS   OF   THE   FIRST    BROOD. 

In  1907  the  first  moth  emerged  August  6,  the  maximum  number 
emerged  August  13,  while  the  last  moth  appeared  September  5;  the 
emergence  period  was  thus  limited  to  thirty  days.  (See  Table  XXXVI 
and  fig.  24.) 


Table  XXXVI. — Emergence  of  first-brood  moths  during  1907. 
material  of  1907  and  reared  specimens. 


From    band-collected 


Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

Date. 

Number          n<* 
of  moths.  ,      Dat€' 

II 

Number 
of  moths. 

Aug.    6 
Aug.    8 
Aug.    9 
Aug.  10 
Aug.  12 
Aug.  13 

1 
2 
1 
5 
6 
18 

Aug.  15 
Aug.  16 
Aug.  17 
Aug.  18 
Aug.  19 
Aug.  20 

1 

5    ' 
5    1 
4 
2 
5 

Aug.  21 
Aug.  22 
Aug.  23 
Aug.  24 
Aug.  25 
Aug.  26 

5 
4 
2 
4 
4 
1 

Aug.  27 
Aug.  30 
Aug.  31 
Sept.    5 

2 
2 
1 
1 

80 

During  1908  the  emergence  period  was  remarkably  extended.  In 
the  cages  the  first  moth  emerged  July  28,  and  the  last  moth  emerged 
September  9,  covering  a  period  of  forty-four  days.  In  Table  XXXVII 
are  given  the  dates  of  emergence  of  the  first-brood  moths  from  band- 
collected  material.     (See  also  fig.  25.) 


CODLING   MOTH  IN   NORTHWESTERN   PENNSYLVANIA.  101 


Fig.  23.— Emergence  curve  of  spring-brood  moths  in  1907,  at  North  East,  Pa.    Records  of  Mr.  P.  R.  Jones. 

(Original.) 


to 

/9 

/* 

/if 
/I 

to 

3 
6 

2 

i          i 

.     f  ' \-  j 

i 

I 

1 

/ 

9           / 

z     / 

/ 

t 

/*       4 

9 

£1      4 

■9 

26       1 

*      3 

o      / 

3 

/> 

r 

t 

Fig.  24.— Emergence  curve  of  first-brood  moths  in  1907,  at  North  East,  Pa.    Records  of  Mr.  P.  R.  Jones. 

(Original.) 


Fig.  25.— Emergence  curve  of  first-brood  moths  in  1908,  at  North  East,  Pa.    From  band-collected 

material.    (Original.) 


102 


DECIDICI rS    FRUIT  INSECTS   AND   INSECTICIDES. 


Table  XXXVII.— Emergence  of  first-brood  moths  during  1908.     From  band-collected 

material. 


Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

Date. 

Number 
of  moths. 

July   28 
July   31 
Aug.    2 
Aug.     3 
Aug.     4 
Aug.     6 

1 

2 
6 
20 
17 
7 

Aug.    7 
Aug.  11 
Aug.  12 
Aug.  14 
Aug.  17 
Aug.  18 

9 

29 

9 

5 

19 

20 

Aug.  19 
Aug.  22 
Aug.  24 
Aug.  26 
Aug.  28 
Aug.  30 

3 
3 
1 

1 
1 
9 

Sept.    2 
Sept.    5 
Sept.    7 
Sept.    9 

4 
1 
3 
2 

172 

BAND   RECORDS   OF   1907   AND   1908. 

For  the  banding  work  in  1907  an  unsprayed  orchard  was  kindly 
placed  at  the  disposal  of  the  Bureau  of  Entomology,  through  the 
courtesy  of  Mr.  W.  Towne,  of  North  East,  Pa. 

After  the  loose  bark  on  the  trunk  and  larger  branches  had  been 
scraped  off,  16  trees  were  properly  banded.  The  banded  trees  were 
examined  once  a  week  from  July  12  to  November  5  for  larvae  and 
pupae.    The  results  of  these  observations  are  given  in  Table  XXXVIII. 

Table  XXXVIII. — Band  records  taken  from  16  apple  trees  during  1907. 


No. 

of  record. 

Date  of 
collecting. 

Number 
of  larvae 

and 
pupae. 

Number 

of 

emerging 

moths. 

No. 
of  record. 

Date  of 
collecting. 

Number 
of  larvae 

and 
pupx. 

Number 

of 

emerging 

moths. 

1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 

July    12 
July   23 
July   27 
Aug.     1 
Aug.    6 
Aug.  11 
Aug.  17 
Aug.  21 
Aug.  26 
Aug.  31 
Sept.    5 
Sept.  11 
Sept.  1G 

14 
15 
16 
17 
18 
19 
20 
21 
22 
23 

Sept.  21 
Sept.  26 
Oct.     1 
Oct.     6 
Oct.    11 
Oct.    16 
Oct.    21 
Oct.    26 
Oct.    31 
Nov.    5 

85 
41 
25 
17 
9 
6 
10 
8 
9 
8 

23 

25 

29 

51 

76 

127 

272 

157 

182 

176 

121 

14 

14 

8 

1 

1,457 

37 

Because  of  the  short  and  cool  season  of  1907,  the  great  majority  of 
the  larvae  of  the  first  brood  wintered,  wlnich  resulted  further  in  a  very 
small  second  generation.  It  is  evident  from  figure  26  that  the  second- 
brood  larvae  constituted  only  a  small  fraction  of  the  total  band  col- 
lection. Since  the  two  broods  of  larvae  evidently  always  overlap,  the 
relative  number  for  each  brood  can  only  be  approximately  estimated. 
Judging  by  the  first  emergence  of  moths  of  the  first  brood  and  by 
other  rearing  records  of  the  year,  the  first  larvae  of  the  second  brood 
reached  maturity  about  October  10.  Judging  by  this  the  entire  band 
collection  would  consist  of  96.5  per  cent  of  first-brood  larvae  and  3.5 
per  cent  of  second-brood  larvae.  Considering,  further,  that  out  of  the 
1,400  larvae  of  the  first  brood  only  37  individuals  transformed,  while 
the  rest  wintered,  it  can  be  figured  approximately  that  only  3  per 
cent  of  the  first-brood  larvae  transformed,  while  97  per  cent  wintered. 


CODLING   MOTH   IN  NORTHWESTERN   PENNSYLVANIA. 


103 


In  1908  the  band-record  experiments  were  carried  out  at  Westfield, 
N.  Y.,  in  an  unsprayed  orchard  consisting  of  large  apple  trees  belong- 
ing to  Mr.  George  Walker  and  kindly  placed  at  the  disposal  of  the 
Bureau  of  Entomology.     The  bands  were  examined  once  a  week,  and 


Fig.  26.— Band-record  curve  of  1907,  at  North  East,  Pa.    (Original.) 

the  larvae  were  counted  and  removed  to  the  laboratory  for  further 
observations.  As  is  evident  from  figure  27,  the  bands  were  placed  on 
the  trees  about  one  week  too  late,  so  that  no  record  was  obtained  of 
the  earliest  maturing:  larvae.     The  two  broods  are  here  clearlv  dis- 


Fig.  27.— Band-record  curves  of  1908,  at  Westfield,  N.  Y.    (Original.) 

tinguishable,  overlapping   but  slightly  at  the  end  of  August.     The 
great  drop  in  the  number  of  larvae  in  early  October  (fig.  27)  was  due 
to  cold  weather.     In  Table  XXXIX  is  given  the  full  record  of  the  band 
collections  for  1908,  with  a  summary  in  Table  XL. 
30490°— Bull.  80—12 8 


104  DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 

Table  XXXIX. — Band  records  taken  from  ten  apple  trees  during  1908. 


No.  of 
record. 

Date  of 
collect- 
ing. 

Number 
of  larva.' 

and 
pupae. 

Number  of 

emerging 

moths. 

1908. 

1909. 

1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 

July   18 
July  25 
Aug.    1 
Aug.    8 
Aug.  14 
Aug.  22 
Aug.  29 
Sept.    5 
Sept.  12 
Sept.  19 
Sept.  27 
Oct.     3 
Oct.    12 
Oct.    18 
Oct.    26 
Nov.    2 
Nov.    9 

84 
77 
121 
90 
54 
52 
20 
27 
102 
105 
101 
29 
85 
28 
10 
6 
2 

66 
69 
87 
25 
4 
1 

1 
1 

13 
27 
33 
38 
14 
25 
43 
92 
56 
26 
50 
20 
7 
2 
1 

993 

252 

449 

Table  XL.— Band  records  of  1908.     Summary  of  Table  XXXIX. 


Larvae  from  band  collections. 


Transforming  larva?  of  band  collections 

Wintering  larvae  of  band  collections 

Relative  proportion  of  first-brood  larvae. . . 
Relative  proportion  of  second-brood  larvae 

Transforming  larva?  of  first  brood 

Wintering  larva?  of  first  brood 

Parasitized,  injured,  and  dead  larvae 


Percent- 
age. 


35.9 

64.1 

50 

50 

67.7 

32.3 

30.1 


WEATHER  RECORDS  FOR  1907,  1908,  AND  1909. 

During  the  three  seasons  that  the  life  history  of  the  codling  moth 
has  been  studied  in  northwestern  Pennsylvania  (1907-1909)  daily 
records  have  been  kept  of  the  maximum  and  minimum  temperatures, 
together  with  other  climatic  conditions.  In  preparing  the  tempera- 
ture curves  shown  in  figures  28-30  use  has  also  been  made  of  the 
weather  records  of  the  Weather  Bureau  made  at  Erie,  Pa. 

The  climatic  conditions  have  been  strikingly  different  during  the 
three  seasons.  The  year  1907  was  marked  by  an  abnormally  low 
temperature,  a  late  spring,  and  an  early  fall  with  a  rather  high  pre- 
cipitation for  the  summer  months.  The  month  of  May  wras  the 
coldest  on  record  during  a  period  of  eighteen  years.  In  1908,  on  the 
contrary,  the  spring  was  very  early,  the  mean  temperature  was  above 
normal,  and  the  summer  was  marked  by  two  periods  of  severe 
drought,  the  dry  condition  being  especially  felt  during  the  latter 
part  of  August.     In  most  respects  1909  was  considered  normal. 

By  comparing  the  daily  fluctuations  of  temperature  with  the  various 
records  showing  the  behavior  of  the  codling  moth  it  will  be  found 


CODLING   MOTH   IN   NORTHWESTERN   PENNSYLVANIA. 


105 


106 


DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 


CODLING  MOTH   IN  NORTHWESTERN   PENNSYLVANIA. 


107 


108 


DECIDUOUS  FRUIT  INSECTS   AND   INSECTICIDES. 


that  its  development  has  been  greatly  influenced  by  the  temperature. 
A  cold  spell  was  invariably  followed  by  a  delay  in  transformation, 
while  a  rise  in  temperature  produced  a  corresponding  hastening  in 
development. 

COMPARATIVE    LIFE-HISTORY    STUDIES    FOR   THE    SEASONS   OF 

1907,  1908,  AND  1909. 

On  considering  the  records  of  the  emergence  of  the  moths  (fig.  31) 
and  the  time  of  maturity  and  relative  abundance  of  larva?  (fig.  32) 
for  the  three  years  under  consideration,  it  is  evident  that  the  codling 
moth  in  its  development  is  greatly  influenced  by  seasonal  conditions. 


MAY 

JUNE 

JULY 

AUG. 

SEPT. 

15    20  25  3 

1     5    10    15   £0  25  3 

0    5     10    15    20   25  3 

1     5    10    15    10  25  3 

1     5     10    15    20 

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i 

J 

f 

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t 

V 

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Fig.  31.— Time  of  emergence  of  spring-brood  and  first-brood  moths,  and  the  blossom  periods  of  apple 
trees,  during  19C7, 1908,  and  1909,  at  North  East,  Pa.    (Original.) 

The  cold  and  wet  spring  of  1907  limited  the  emergence  of  the  spring 
moths  to  a  short  period.  The  prevailing  low  temperature  delayed 
the  larvae  to  such  an  extent  that  only  3  per  cent  of  the  first  brood 
transformed.  The  entire  second  generation  was  reduced  to  3.5  per 
cent  against  96.5  per  cent  of  the  first  generation. 

The  season  of  1908  was  evidently  very  favorable  for  the  develop- 
ment of  the  codling  moth.  The  early  spring  brought  out  the  moths 
by  May  25.  During  the  long  and  warm  summer  the  majority  of  the 
larvtt  of  the  first  brood  transformed  in  great  numbers  (only  32.3  per 
cent  wintered),  and  the  following  brood  of  larvae  attained  a  size  equal 
to  that  of  the  first  brood. 


CODLING   MOTH   IN  NORTHWESTERN   PENNSYLVANIA. 


109 


The  development  of  the  insect  in  1909  was  about  intermediate  as 
compared  with  the  results  of  the  previous  years.  The  early  fall  was 
quite  variable,  changing  frequently  from  warm  to  extremely  cold, 
resulting  in  a  sudden  stop  in  the  transformation  of  late  larvae  of  the 
first  brood;  the  oviposition  period  for  the  second  brood  became 
limited  and  also  late  deposited  eggs  failed  to  hatch.  A  number  of 
larvae  of  the  second  brood  spun  up  before  they  became  full  grown  and 
several  did  not  reach  hibernating  places  before  freezing  temperature 
set  in.  Of  the  insects  developed  during  1909  83.87  per  cent  were  of 
the  first  generation  and  16.13  per  cent  of  the  second  generation.  Of 
the  first-brood  larvae  23.46  per  cent  transformed,  while  76.54  per  cent 


Fig.  32.— Time  of  leaving  the  fruit  of  the  first-brood  and  second-brood  larvae  of  the  codling  moth,  during 
1907, 1908,  and  1909,  at  North  East,  Pa.    (Original.) 

wintered.     A  summary  of  the  results  of  life-history  studies  for  these 
three  years  is  given  in  Table  XLI.     (See  also  figs.  31  and  32.) 

Table  XLI.—  Summary  of  results  of  band  records  for  1907,  1908,  and  1909,  showing  the 
comparative  size  of  broods  and  relative  number  of  transforming  and  wintering  larvae. 


Larvae  from  band  collections. 

Percentages  for— 

1907. 

1908. 

1909. 

Transforming  larvae  of  total  band  collection 

2.5 
97.5 
96.5 

3.5 

3 
97 

35.9 

64.1 

50 

50 

67.7 

32.3 

18.74 
81.26 
83.87 
16.13 
23.46 
76.54 

Wintering  larvae  of  total  band  collection 

Relative  proportion  of  first-brood  larvae 

Relative  proportion  of  second-brood  larvae 

Transforming  larvae  of  first  brood 

Wintering  larvae  of  first  brood 

110  DECIDUOUS   FRUIT    INSECTS   AND    INSECTICIDES. 

INSECT  ENEMIES. 

The  feeding  habits  of  codling-moth  larva?  within  the  fruit  offer 
the  insect  considerable  protection  against  both  predaceous  and  para- 
sitic enemies.  At  the  time  of  maturity,  however,  when  the  larvae 
leave  the  fruit  and  seek  suitable  places  for  transformation  or  hiber- 
nation, they  are  for  a  short  time  exposed  and  are  sometimes  attacked 
by  various  insect  enemies.  A  small  black  beetle  (Tenebrioides  cor- 
ttcalis  Melsh.)  and  its  very  slender  larva  were  found  during  August 
to  late  October,  1909,  under  the  burlap  bands  on  apple  trees.  Dead 
and  partly  devoured  codling-moth  larva?  were  frequently  found 
attacked  by  both  beetles  and  larva?  of  this  species.  Another  black 
beetle,  Dromius  piceus  Dej.,  was  also  found  quite  frequently.  Platy- 
nus  obsoletus  Say  was  taken  on  several  occasions,  and  a  few  specimens 
of  the  larger  ground  beetle  (Galerita  janus  Fab.)  were  also  collected 
under  the  bands. 

The  following  beetles  were  collected  from  banded  trees,  but  without 
any  observation  as  to  their  attacks  upon  larva?  of  the  codling  moth: 
Melanotus  fissilis  Say,  Cryptarcha  ampla  Er.,  Mycetochares  fraterna 
Say,  Tenebrio  tenebrioides  Beau  v.,  and  Hymenorus  sp.  These  and 
previously  named  beetles  were  determined  by  Messrs.  E.  A.  Schwarz 
and  H.  S.  Barber,  of  the  Bureau  of  Entomology. 

The  following  species  of  ants,  determined  by  Mr.  Theo.  Pergande, 
were  found  to  attack  the  larva?  of  the  codling  moth  under  the  bands : 
Camponotus  pennsylvanicus  (Dej.)  Mayr.,  Formica  subsericea  Say, 
Cremastogaster  lineolata  Say,  and  Myrmica  lobicomis  Xyl. 

A  centipede,  Geophilus  rubens  Say,  determined  b}'  Mr.  R.  Y.  Cham- 
berlin,  of  Provo,  Utah,  was  taken  several  times  beneath  the  bands, 
in  the  act  of  feeding  on  larva?  of  the  codling  moth. 

A  hymenopterous  parasite  (Ascogaster  carpocapsse  Tier.),  as  deter- 
mined by  Mr.  H.  L.  Yiereck,  of  the  Bureau  of  Entomology,  issued  in 
the  cages  from  band  material  of  the  two  broods  of  the  codling  moth, 
and  proved  to  be  quite  common. 

SUMMARY. 

In  northwestern  Pennsylvania  the  codling  moth  produces  in  the 
course  of  a  year  one  full  generation  and  a  partial  second  generation. 

The  life-cycle  of  the  insect  may  be  briefly  summarized  as  follows: 
In  the  spring  the  overwintering  larva  pupates  in  early  June,  and 
three  weeks  later  the  moth  emerges.  The  emergence  extends  over 
a  period  of  about  1  month,  beginning  about  the  middle  of  June. 
Oviposition  generally  takes  place  3  or  4  days  after  the  emergence 
of  the  moth,  and  the  egg  hatches  in  1  week.  Eggs  showing  a 
red  ring  are  about  3  days  old,  while  those  with  a  black  spot  in  the  cen- 
ter will  mostly  hatch  in  1  or  2  days.  Shortly  after  hatching  the 
young  larva  enters  the  fruit  and  feeds  about  26  days.    _On  reaching 


CODLING   MOTH  IN  NOKTHWESTERN   PENNSYLVANIA.  Ill 

maturity  the  larva  seeks  a  hiding  place  beneath  the  rough  bark  of 
the  trunk  of  the  tree  and  constructs  a  cocoon  within  which  pupation 
takes  place  about  1  week  after  the  larva  left  the  fruit.  Some  of  the 
larvae  do  not  pupate  at  this  time  but  winter,  and  the  moths  emerge 
the  following  spring,  together  with  moths  from  second-brood  larvae. 
The  pupal  stage — called  the  first-brood  pupae,  though  the  second  set 
of  pupae  of  the  season — lasts  on  an  average  12  days.  The  emergence 
period  of  this  second  set  of  moths,  called  first-brood  moths,  begins 
in  early  August  and  lasts  about  1  month.  With  the  appearance  of 
new  eggs,  resulting  from  the  first-brood  moths,  the  life-cycle  of  the 
first  generation  is  completed,  covering  on  an  average  58  days.  The 
second-brood  eggs  hatch  generally  within  9  days  and  the  resulting 
larvae  feed  about  40  days,  after  which  they  enter  hibernation,  making 
cocoons  beneath  the  rough  bark  on  the  trunk  of  the  trees.  The  life- 
cycle  of  the  second  generation  and  part  of  the  first  generation  is  first 
completed  with  the  transformation  of  the  insect  the  following  spring. 
The  period  covered  by  the  different  stages  of  the  two  broods  for  1909, 
as  shown  in  figure  22,  closely  represents  average  conditions. 

The  relative  number  of  transforming  larvae  of  the  first  brood  is 
variable  under  different  seasonal  conditions. 

The  relative  abundance  of  second-brood  larvae  depends  more 
upon  seasonal  conditions  and  food  supply  than  upon  the  number  of 
transforming  larvae  of  the  first  brood. 

Larvae  of  the  second  brood  are  always  present  in  injurious  numbers, 
so  that  measures  should  be  taken  to  combat  the  second  as  well  as  the 
first  brood. 

The  time  of  the  emergence  of  the  spring  brood  of  the  moths  is  vari- 
able under  different  seasonal  conditions  and  depends  largely  upon 
the  relative  lateness  of  the  spring. 

The  time  of  emergence  of  the  summer  brood  or  first  brood  of  moths 
is  fairly  constant  and  generally  commences  about  the  1st  of  August. 

In  the  control  of  the  codling  moth  with  poison  sprays  three  appli- 
cations should  be  made  in  this  section  of  the  country.  The  first 
application  should  be  made  after  the  blossom  period  just  after  the 
petals  drop,  the  second  application  from  3  to  4  weeks  later,  and  the 
third  application  from  9  to  10  weeks  after  the  petals  drop,  or  about 
the  1st  of  August. 


U.  S.  D.  A.,  B.  E.  Bui.  80,  Part  VII  (Revised).  D.  F.  I.  I.,  March  30,  1911. 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


THE    ONE-SPRAY    METHOD    IN    THE    CONTROL    OF    THE 
CODLING   MOTH  AND   THE  PLUM   CURCULIO. 

By  A.  L.  Quaintance, 
In  Charge  of  Deciduous  Fruit  Insect  Investigations, 

AND 

E.  L.  Jexne,  E.  W.  Scott,  and  R.  W.  Braucher, 

Engaged  in  Deciduous  Fruit  Insect  Investigations. 

INTRODUCTION. 

The  so-called  one-spray  method  of  spraying  for  the  codling  moth 
on  apples  consists  essentially  in  making  the  application  following  the 
dropping  of  the  petals  so  thorough  that  it  will  result  in  the  practical 
extermination  of  the  first  brood  of  larvae,  subsequent  treatments, 
therefore,  becoming  unnecessary.  This  method  of  spraying  has 
come  into  considerable  use  in  the  Northwest  following  the  investiga- 
tions of  Dr.  E.  D.  Ball,  in  Utah,  and  Prof.  A.  L.  Melander,  in  Wash- 
ington, and  its  applicability  for  the  control  of  the  codling  moth  under 
eastern  conditions  has  been  strongly  urged.  The  subject  has  already 
received  attention  at  the  hands  of  several  eastern  entomologists, 
notably  Gossard,  in  Ohio,  Sanderson,  in  New  Hampshire,  Felt,  in 
New  York,  and  Rumsey,  in  West  Virginia.  It  is  not  within  the  scope 
of  the  present  paper,  which  is  in  the  nature  of  a  preliminary  report, 
to  review  the  present  status  of  the  one-spray  method.  On  the  whole, 
however,  it  has  appeared  to  the  writers  from  a  study  of  the  experi- 
ments thus  far  reported  as  bearing  directly  upon  the  control  of  the 
codling  moth,  that  most  of  these  have  been  more  or  less  inconclusive 
as  not  having  fully  met  the  conditions  stated  to  be  essential  for  suc- 
cessful one-spray  work.  The  indispensable  requisite  is  stated  to  be 
the  placing  of  necessary  poison  in  the  inner  calyx  cup.  By  referring 
to  figure  33  the  structure  of  the  calyx  end  of  a  young  apple  may  be 
noted,  namely,  that  there  are  two  cavities,  one  above  and  one  below 
the  stamen  bars  or  filaments.  The  observations  of  Doctor  Ball  led 
him  to  believe  that  the  great  majority  of  codling-moth  larva?  in  seek- 
ing entrance  at  the  calyx  end  of  the  apple  enter  through  the  lower 

113 


114 


DECIDUOUS   FRUIT   INSECTS    AND   INSECTICIDES. 


calyx  cup,  and  would  thus  mostly  escape  destruction  unless  the  poison 
had  been  there  placed.  Other  investigators  have  shown,  notably  the 
late  Professor  Slingerland,  that  codling-moth  larvae  in  the  East  feed 
in  the  outer  calyx  cup,  and  the  results  which  have  been  obtained  with 
mist  sprays  in  the  East  during  the  past  twenty-five  years,  filling 
mostly  only  the  outer  calyx  cavity,  have  been  much  more  favorable 
than  could  be  expected  were  it  the  rule  that  feeding  occurs  principally 
in  the  inner  cup.  The  stamen  bars,  as  shown  in  the  figure,  form  a 
dome  or  shield  over  the  cavity  below,  and  the  poison  is  best  forced 


2(i 


Fig.  33.— The  condition  of  the  calyx  cup  of  the  apple  in  relation  to  spraying  for  the  codling  moth:  Fig.  U— 
A  calyx  cup,  five  days  after  the  petals  fell,  split  open  to  show  two  cavities;  la,  the  roof  of  stamens  as  seen 
from  above.  Fig.  2.—\  calyx  cup  two  weeks  after  blossoming,  showing  the  calyx  lobes  above;  2a,  the 
stamens  from  above  to  show  spaces.  Fig.  5.— The  relation  of  fhc  two  cavities  in  a  nearly  grown  apple; 
Sa,  stamens  from  above.    (From  Ball.) 

through  these  bars  by  a  coarse,  forceful  spray,  as  from  a  Bordeaux 
nozzle  and  with  a  pump  pressure  of  from  175  to  200  or  more  pounds. 
It  is  also  required  that  the  work  of  spraying  be  done  very  thoroughly, 
the  spray  being  directed  from  above  into  each  and  every  fruit  cluster. 
The  use  of  an  elbow  or  crook  between  the  rod  and  nozzle  to  incline 
the  nozzle  at  an  angle  of  from  30  to  45  degrees  with  the  spray  rod 
permits  of  better  directing  the  spray  downward,  and  oven  in  the  case 
of  small  trees  it  is  recommended  to  spray  from  a  platform  on  the 
wagon.  The  employment  of  a  coarse  nozzle  and  a  high  pressure  uses 
a  large  amount  of  spray  before  the  trees  are  properly  sprayed,  literally 
drenching  the  trees. 


ONE-SPRAY   METHOD  FOR   CODLING   MOTH,  ETC.  115 

This  single  treatment,  as  above  described,  made  just  after  the 
falling  of  the  petals,  in  the  experience  of  Professor  Melander  has  been 
sufficient  to  keep  the  codling  moth  under  complete  control.  Doctor 
Ball,  however,  inclines  to  two  early  treatments,  the  second  being 
given  before  the  calyx  lobes  entirely  close,  as  within  ten  days  after 
the  falling  of  the  petals.  At  the  time  of  this  latter  treatment  the 
stamen  bars  have  become  more  or  less  shriveled  and  more  readily 
permit  the  entrance  of  the  spray  into  the  inner  calyx  cup.  The  two 
practices  as  recommended  by  Professors  Ball  and  Melander  do  not 
differ  in  principle,  however,  and  Doctor  Ball's  second  treatment  is  in 
the  nature  of  a  supplementary  one.  In  summing  up  his  experiments, 
covering  several  years  in  Utah,  Doctor  Ball  states  his  conclusions  as 
follows  :a 

The  first  early  spray  is  the  best,  the  second  is  nearly  as  good,  and  the  third  is  of 
little  value. 

TVo  early  driving  sprays  will  kill  an  average  of  90  per  cent  of  the  first  brood  of 
worms. 

Sufficient  poison  is  retained  [in  calyx  cup]  from  the  early  sprayings  to  kill  an  average 
of  74  per  cent  of  the  second  brood  of  worms. 

Two  early  sprayings  correctly  applied  are  worth  from  6  to  16  times  as  much  as  three 
late  ones. 

Professor  Melander  says:  6 

A  single  thorough  spraying  has  afforded  practically  100  per  cent  returns  over  hun- 
dreds and  hundreds  of  acres  of  Washington  orchards.  The  same  benefit  from  the 
single  spraying  has  also  been  abundantly  attained  in  Colorado  and  TTtah. 

Aside  from  the  particular  question  involved  as  to  whether  the  one- 
spray  method  will  sufficiently  control  the  codling  moth  under  eastern 
conditions,  several  other  considerations  must  be  taken  into  account. 

In  the  arid  valleys  of  the  West,  as  in  Utah,  Washington,  and  Colo- 
rado, practically  the  only  important  insect  enemy  of  the  fruit  of  the 
apple  is  the  codling  moth,  and  fungous  diseases  are,  on  the  whole, 
of  but  little  importance.  The  use  of  fungicides  is  therefore  not  ordi- 
narily necessary  and  there  is  thus  to  be  controlled  only  the  codling 
moth. 

In  the  Mississippi  Valley  and  Eastern  States,  however,  and  in 
central  and  eastern  Canada,  there  are,  in  addition  to  the  codling  moth, 
the  apple  and  plum  curculios  and  the  lesser  apple  worm,  winch  in 
many  sections  are  exceedingly  injurious,  the  plum  curculio  in  some 
parts  being  scarcely  less  in  importance  than  the  codling  moth  itself. 
Furthermore,  the  general  prevalence  of  fungous  diseases,  such  as  the 
apple  scab,  apple  fruit  blotch,  bitter  rot,  and  leaf-spot  affections, 
requires  several  fungicidal  treatments  during  the  season.     Entomolo- 

oBul.  67,  Bur.  Ent.,  U.  S.  Dept.  Agr.,  p.  75,  1907. 
&  Journal  of  Economic  Entomology,  vol.  2,  p.  67,  1909. 


116  DECIDUOUS  FRUIT  INSECTS   AND  INSECTICIDES. 

gists  and  plant  pathologists  have  by  many  experiments  determined  a 
schedule  of  spraying  with  a  combined  arsenical  insecticide  and  a  fungi- 
cide— Bordeaux  mixture  or  lime-sulphur  wash — which  affords  a  large 
degree  of  protection  from  all  of  these  troubles.  To  effect  the  control 
of  insects  other  than  the  codling  moth  and  the  several  fungous  dis- 
eases mentioned  requires  several  applications  of  sprays,  and  renders 
the  one-spray  method  of  questionable  practical  value  where  these 
several  troubles  exist.  These  differences  in  fruit-growing  conditions 
between  the  West  and  East  should  be  borne  in  mind  in  any  consid- 
eration of  the  practicability  of  the  one-spray  method. 

BESULTS  OF  EXPERIMENTS  WITH  THE  ONE-SPRAY  METHOD  AS 
COMPARED  WITH  RESULTS  FROM  THE  USUAL  SCHEDULE  OF 
APPLICATIONS. 

During  the  season  of  1909  the  Bureau  of  Entomology  carried  out 
experiments  to  determine  the  relative  value,  in  the  control  of  the 
codling  moth  and  plum  curculio  under  eastern  conditions,  of  the 
one-spray  method  in  comparison  with  a  schedule  of  applications 
requiring  a  total  of  from  three  to  five  treatments  according  to  locality, 
representing  practically  the  method  of  spraying  considered  best  for 
the  localities  in  question.  The  work  was  carried  out  in  three  States, 
namely,  in  Virginia,  in  Arkansas,  and  in  Michigan,  and  included  four 
orchards,  thus  representing  a  considerable  range  in  climatic  conditions. 
The  field  work  in  Arkansas  was  under  the  immediate  direction  of 
Mr.  E.  L.  Jenne,  assisted  by  Mr.  F.  W.  Faurot;  in  Virginia  the  field 
operations  were  under  the  immediate  charge  of  Mr.  E.  W.  Scott, 
assisted  by  Mr.  L.  F.  Pierce,  of  the  Bureau  of  Plant  Industry.  Mr. 
R.  W.Braucher  was  charged  with  the  spraying  operations  in  Michigan, 
and  was  assisted  a  part  of  the  time  by  Mr.  Walter  Postiff.  The  work 
relating  to  the  control  of  fungous  diseases  in  each  of  the  orchards  was 
done  in  cooperation  with  Mr.  W.  M.  Scott,  of  the  Bureau  of  Plant 
Industry.  In  addition  to  obtaining  data  on  the  effects  of  the  treat- 
ments on  the  codling  moth  and  plum  curculio,  in  Arkansas  injury  by 
the  lesser  apple  worm  was  taken  into  account,  which  in  that  section 
is  very  troublesome. 

EXPERIMENTS  IN  ARKANSAS. 

The  experiments  in  Arkansas  were  carried  out  in  the  orchard  of 
M  is.  S.  E.  Jones  in  the  vicinity  of  Siloam  Springs.  The  entire  orchard, 
consisting  of  344  trees,  was  divided  into  five  plats,  as  shown  in  the 
accompanying  diagram  (fig.  34.)  Trees  of  each  plat  from  which  the 
fruit  was  counted  throughout  the  season  for  records  are  designated 
in  the  diagram  by  the  same  numbers  which  these  trees  bear  in  the 
table.     The  orchard,  a  general  view  of  which  is  shown  in  Plate  X, 


Bui.  80,  Part  VII,  Revised,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture 


Plate  X. 


Fig.  1  .—View  in  Orchard  of  Mrs.  S.  E.  Jones,  near  Siloam  Springs,  Ark.    (Original.) 


Fig.  2.— View  in  Orchard  of  Mr.  W.  S.  Ballard,  near  Crozet,  Va.    (Original. 


ONE-SPRAY  METHOD  FOR   CODLIXG  MOTH,  ETC. 


117 


figure  1,  is  an  isolated  one  and  the  location  very  favorable  for  the 
work  in  hand.  Plat  I  included  7  rows,  Plat  II  a  single  row,  Plat  III 
3  rows,  Plat  TV  5  rows,  and  Plat  V  (the  unsprayed  plat)  included 
5  rows,  this  last  plat  being  at  one  end  of  the  orchard.     The  orchard 


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Fig.  34.— Diagram  of  the  Mrs.  S.  E.  Jones  orchard,  Siloam  Springs,  Ark.,  showing  location  of  plats  and 
trees  used  for  making  counts  of  fruit:  D,  Ben  Davis  variety;  A,  Arkansas  Black;  T,  Mammoth  Black 
Twig;  W,  Winesap;  /,  Jonathan;  mp,  Missouri  Pippin;  wp,  White  Wirter  Pearmain,  etc.  Trees  of  Ben 
Davis  variety  only  were  used  for  making  counts  of  fruit.  These  are  indicated  for  the  respective  plats 
by  a  circle,  the  numbers  agreeing  with  the  numbers  of  these  trees  in  the  tables.    (Original.) 

included  a  miscellaneous  assortment  of  varieties,  as  shown  by  the 
legend  under  figure  3-4,  but  principally  the  Ben  Davis,  on  which 
variety  counts  were  made.  The  treatments  to  which  the  respective 
plats  were  subjected  are  shown  in  Table  I. 


118 


DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


Table  I. — Treatments  and  dates  of  applications  of  sprays  for  the  codling  moth  and  plum 
curculio.     One-spray  method.    Siloam  Springs,  Ark.,  1909. 


Dates  of  applica- 

Plat I. 

Plat  II. 

tions. 

(One-spray  method.) 

(One-spray  method.) 

First      application, 
April    24-26  (after 
failing  of  petals). 

Drenched  with  arsenate  of  lead.   1  pound 

Drenched  with  arsenate  of  lead.   1  pound 

to  50  gallons  of  water.     Bordeaux  noz- 

to 50  gallons  Bordeaux  mixture  (3-3- 
50).     Bordeaux    nozzles.     17     gallons 

zles.     17  gallons  per  tree.    200  pounds 

pressure. 

per  tree.    200  pounds  pressure. 

Second  application, 

Bordeaux  mixture  only  (4-4-50).     Bor- 

Bordeaux mixture  only  (4-4-50).     Bor- 

May 25-2<;. 
Third     application, 
July  2. 

deaux  nozzles. 

deaux  nozzles. 

do 

Do. 

Fourth  application, 

July  22. 
Fifth      application, 

August  10. 

Unsprayed 

Unsprayed. 
Do. 

do 

Dates  of  applica- 

Plat III. 

Plat  IV. 

Plat  V. 

tions. 

(One-spray  method.) 

(Demonstration.) 

(Unsprayed.) 

First     application, 
April  24-25  (after 
falling  of  petals). 

Drenched  with  arsenate  of  lead. 

Not  drenched.    Vermorel  noz- 

Unsprayed. 

1  pound  to 50  gallons  of  water. 

zles.      Mist  spray,  arsenate 
of  lead.    2  pounds  to  50  gal- 

Vermorel   nozzles.         Mist 

spray.     8.3  gallons  per  tree. 

lons  Bordeaux  mixture  (3- 

200  pounds  pressure. 

3-50).    11  gallons  per  tree. 
200  pounds  pressure. 

Second  application, 
May  25-26. 

Bordeaux  mixture  only  (4-4- 

Bordeaux    mixture    (4-4-50) 

Do. 

50).    Mist  spray.    Vermorel 

with  2  pounds  arsenate  of 
lead.     Mist  spray.     Vermo- 

nozzles. 

rel  nozzles. 

Third   application, 

do 

Bordeaux    mixture    (4-4-50) 

Bordeaux  mixture 

July  2. 

with  2  pounds  arsenate  of 
lead.     Mist  sprav.     Vermo- 

only (4-4-50). 

rel  nozzles. 

Fourth  application, 

July  22. 
Fifth     application, 

August  10. 

do 

Unsprayed. 
Do. 

do 

do 

Plats  I,  II,  and  III  received  an  arsenical  treatment  of  1  pound  of 
arsenate  of  lead  to  50  gallons  of  water  immediately  after  the  falling 
of  the  petals.  Two  subsequent  applications  of  Bordeaux  mixture 
only  were  made  to  protect  the  fruit  from  the  apple  blotch  and  bitter 
rot  and  one  Bordeaux  treatment  was  also  given  to  the  check  plat 
(Plat  V)  for  the  same  purpose,  as  these  affections  in  this  locality  are 
exceedingly  troublesome  and  otherwise  would  have  interfered 
greatly  with  results.  Plat  IV,  which  received  demonstration  treat- 
ment, received  five  applications  in  all,  as  shown,  of  a  combined  spray 
of  Bordeaux  mixture  and  arsenate  of  lead,  the  latter  being  used  at 
the  rate  of  2  pounds  to  50  gallons  of  spray.  On  the  demonstration 
plat  the  usual  eddy  chamber,  or  Vermorel  nozzle,  was  used  and  while 
mi  effort  was  made  to  spray  thoroughly  according  to  usual  recom- 
mendations in  the  East,  the  drenching  of  the  trees  was  carefully 
avoided.  Plat  I,  which  received  the  one-spray  treatment  proper, 
was  very  thoroughly  treated  and  required  an  average  of  17  gallons 
per  tree.  The  Bordeaux  nozzle  was  used  with  a  crook  between  the 
nozzle  and  spray  rod  and  a  pressure  was  maintained  at  about  200 
pounds.  Plat  II  received  exactly  the  same  treatment  except  that 
arsenate  of  lead  was  applied  in  dilute  Bordeaux  mixture  to  determine 


ONE-SPRAY   METHOD  FOE   CODLING   MOTH,  ETC. 


119 


to  what  extent  russeting  of  the  fruit  might  result  from  so  liberal  a 
use  of  the  fungicide.  The  treatment  for  Plat  III  was  identical  with 
that  for  Plat  I,  except  that  Vermorel  nozzles  were  used.  It  was 
desired  to  determine  the  comparative  merits  of  a  mist  spray  as  against 
a  coarse  spray,  and  it  will  be  noted  that  the  quantity  of  liquids  required 
per  tree  for  the  mist  spray  (Plat  III)  was  somewhat  less  than  one-half 
the  amount  necessary  in  the  drenching  work  (Plat  I). 

The  results  presented  include  all  of  the  drop  fruit  throughout  the 
season  and  the  fruit  from  the  trees  at  picking  time  in  the  fall.  All 
apples  were  carefully  examined  as  to  worminess  from  the  codling  moth 
and  as  to  injury  by  the  plum  curculio  and  lesser  apple  worm.  Fruit 
from  Plats  I  and  III  was  badly  injured  by  the  apple  blotch,  which 
can  be  accounted  for  only  by  the  omission  of  Bordeaux  mixture  from 
the  treatment  given  immediately  after  the  falling  of  the  petals. 
Fruit  from  Plat  II,  which  had  been  thoroughly  drenched  with  Bor- 
deaux mixture  using  Bordeaux  nozzles,  was  not  noticeably  more 
russeted  than  in  the  case  of  fruit  from  the  demonstration  plat  and 
was  free  from  apple  blotch.  Plat  IV  showed  some  infection  from 
scab  owing  to  the  fact  that  it  had  not  been  sprayed  with  Bordeaux 
mixture  before  the  blossoms  opened. 

THE    CODLING    MOTH. 

In  Table  II  are  shown  results  of  treatments  of  Plats  I,  III,  IV,  and 
V  as  to  injury  from  the  codling  moth.  Plat  II  is  not  here  considered 
nor  subsequently,  as  the  point  involved,  namely,  the  effect  on  the 
fruit  of  a  drenching  spray  of  arsenate  of  lead  and  Bordeaux  mixture 
after  the  falling  of  the  petals,  has  already  been  indicated.  There  was 
not  noticeably  more  russeting  of  the  fruit  on  Plat  II  than  on  Plat  IV 
which  received  the  demonstration  treatment. 


Table  II. — Sound  and  wormy  apples  from  one-spray,  demonstration,  and  unsprayed 
plats.    Siloam  Springs,  Ark.,  1909. 

PLAT  I.     ONE  SPRAY  (BORDEAUX  NOZZLES). 


Condition  of  fruit. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

Wormy 

703 
4,986 

522 

4,291 

419 

3.377 

118 
2,632 

181 
3.265 

222 

3,540 

286 
3,021 

315 

5,128 

Total 

5.689 
87.65 

4,813 
89.16 

3.796 
88.97 

2,750 
95.71 

3.446 
94.74 

3.762 
94.19 

3.307 
91.36 

5.443 

Per  cent  sound 

94.22 

Condition  of  fruit. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

Total  for 
plat. 

Total 
percent 
sound. 

Wormy 

110 
3,489 

113 
2,539 

131 
3,764 

3,120 
40,032 

Sound 

Total 

3,599 
96.95 

2,652 
95.71 

3.895 
96.69 

43,152 

Ppr  c*>nt.  snrmrl 

<W  7fi 

30490°— Bull.  80—12- 


120 


DECIDUOUS    FRUIT    INSECTS    AND    INSECTICIDES. 


Table  II. — Sound  and  wormy  apples  from  one-spray,  demonstration,  and  umprayed 
plats.     Siloam  Springs,  Ark.,  1909 — Continued. 

II. AT  III.  ONE  SPRAY  (VERMOREL  NOZZLES). 


Condition  of  fruit. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

Wormy 

397 
4,352 

298 
3,187 

286 
2,458 

431 
2,221 

321 
1,920 

247 
3,323 

231 

2,650 

200 
1,792 

Sound 

Total 

4,749 
91.65 

3,485 
91.45 

2,744 
89.58 

2,652 
83.79 

2,241 
85.73 

3,570 
93.09 

2.881 
91.99 

1  992 

Per  cent  sound 

89  96 

Condition  of  fruit. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

Total  for 
plat. 

Total 
per  cent 
sound. 

Wormy 

234 
1,986 

2,645 
23,889 

Sound 

Total 

2,220 
89.46 

26,534 

Per  cent  sound 

on  na 

PLAT  IV.  DEMONSTRATION. 


Condition  of  fruit. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

Wormy 

36 
3,500 

41 
1,849 

93 
4,983 

16 
1,649 

22 
3,123 

23 
1,642 

57 
2,439 

57 

3,115 

Total 

3,536 
98.99 

1,890 
97.83 

5,076 
98.17 

1,665 
99.04 

3,145 
99.31 

1,665 
98.62 

2,496 
97.72 

3,172 

Per  cent  sound 

98.21 

Condition  of  fruit. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

Total  for 
plat. 

Total 
per  cent 
sound. 

Wormy 

154 

4,637 

67 
1,890 

41 
3,017 

607 
31,844 

Total. 

4,791 
96.79 

1.957 
96.58 

3,058 
98.66 

32,451 

Per  cent  sound 

98.12 

PLAT  V.  UNSPRAYED. 


Condition  of  fruit. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

Wormy 

795 
1,765 

679 
1,004 

217 

778 

716 
822 

450 
756 

823 
1,678 

697 

2.124 

287 

Round ... 

869 

Total 

2,560 
68.  M 

1,683 
59.66 

995 
78.20 

1.538 
53.45 

1,206 
62.68 

2.501 
67.10 

2.821 
75.30 

1.156 

Per  cent  sound 

75.18 

Condition  of  fruit. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

Total  for 
plat. 

Total 
per  cent 
sound. 

652 

1.671 

859 
1,399 

709 
1,010 

592 
1,016 

644 
1,416 

8,120 
16.308 

Sound 

Total 

2.323 
71.94 

2.258 
61.18 

1,719 
58.76 

1.608 
68.  l'.» 

2,060 
68.74 

24,428 

66.74 

Plat  I,  which  received  the  one- spray  treatment,  shows  an  average 
of  92.76  per  cent  of  fruit  free  from  the  codling  moth,  the  percentages 
for  individual  trees  ranging  from  87.65  to  96.95.     The  total  number 


ONE-SPRAY   METHOD  FOR   CODLING   MOTH,  ETC. 


121 


of  apples  counted  from  this  plat  was  43,152.  Plat  III  received  the 
drenching  mist  spray  with  Vermorel  nozzle  and  shows  for  the  indi- 
vidual trees  a  range  in  percentage  of  fruit  free  from  the  codling  moth 
of  83.79  to  91.99,  with  an  average  for  all  trees  of  90.03.  There  were 
26,534  apples  examined.  Plat  IV,  which  received  the  demonstration 
treatment  of  five  applications,  shows  a  total  from  the  11  trees  of 
98.12  per  cent  of  fruit  free  from  the  codling  moth,  with  a  range  for 
individual  trees  of  96.58  to  99.31  per  cent,  and  the  total  number  of 
apples  counted  was  32,451.  Plat  V  (the  unsprayed  block)  shows,  for 
the  13  trees  from  which  counts  were  made,  66.74  per  cent  of  fruit  free 
from  the  codling  moth,  the  range  being  from  53.45  to  78.20  per  cent, 
the  total  number  of  apples  counted  being  24,428.  Demonstration 
plat,  No.  IV,  shows  an  increase  over  the  unsprayed  trees  of  31.38  per 
cent  of  uninjured  fruit  and  an  increase  of  5.36  per  cent  of  uninjured 
fruit  over  the  one-spray  block  (Plat  I). 

The  percentages  of  sound  fruit  from  Plats  I  and  III  show  very  little 
difference  in  favor  of  a  coarse  spray  over  a  mist  spray;  that  is,  2.73 
per  cent  in  favor  of  the  former. 

In  Table  III  are  shown  the  places  of  entrance  into  apples  of  the 
total  larvae  for  the  season  for  each  tree  of  each  plat  and  also  the  per- 
centages, by  plats,  entering  the  fruit  at  the  calyx,  side,  and  stem. 
These  data  have  been  given  in  order  to  show  what  effect  the  methods 
of  spraying  might  have  upon  the  places  of  entrance  into  fruit  by 
larvae.  The  unsprayed  plat  (Plat  V)  may  be  taken  to  indicate  the 
normal  behavior  of  the  larvae  and  shows  that  of  the  first  brood  76.84 
per  cent  and  of  the  second  brood  80.34  per  cent  entered  the  apples 
at  the  calyx  ends. 

Table  III. — Places  of  entrance  into  fruit  by  total  larvae,  of  the  codling  moth  for  each  tree  of 
each  plat.    Siloam  Springs,  Ark.,  1909. 

PLAT  I.    ONE  SPRAY  (BORDEAUX  NOZZLES). 


Total  number  of  larvae  and  places  of  entrance  of  fruit  for  each  tree,  by  broods. 

Place  of  entrance. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

First  brood: 

Calyx 

1 

Side 

5 

4 

1 

3 

1 

2 

1 

2 

Stem 

Total 

5 

4 

1 

3 

1 

2 

1 

3 

Second  brood: 

Calyx 

91 
557 
53 

70 

400 

48 

69 
323 

27 

20 
77 
18 

32 

137 

12 

31 
172 
24 

54 
198 
34 

55 

Side 

235 

Stem 

25 

Total 

701 

518 

419 

115 

181 

227 

286 

315 

122 


DECIDUOUS  FRUIT   INSECTS   AND  INSECTICIDES. 


Table  III. — Place*  of  entrance  into  fruit  by  total  larvse  of  the  codling  moth  for  each  tree  of 
each  plat.    Siloam  Springs,  Ark.,  1909— Continued. 

PLAT  I.    ONE  SPRAY-Continued. 


Total  number  of  larvae  and  places  of  entrance  of  fruit  for  each  tree,  by 
broods. 

Total 
for 
plat. 

Percent- 
age of 
larvae  by 
broods 
entering 
at  calyx, 
side,  and 
stem. 

Total 
larvae, 
first  and 
second 
broods. 

Place  of  entrance. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree 
12. 

Tree 
13. 

First  brood: 

Calyx 

2 
1 

1 
1 

4 
22 

15.38 
84.62 

Side 

1 

Stem 

Total 

3 

2 

1 

26 

Second  brood: 

{"fl^X 

32 
110 
11 

24 

80 

9 

26 
89 
15 

504 

2,378 

276 

15.97 
75.30 
8.73 

Side 

Stem 

Total 

153 

113 

130 

3, 158 

3,184 

PLAT  III.    ONE  SPRAY  (VERMOREL  NOZZLES). 


Total  number  of  larvae  and  places  of  entrance  of  fruit  for  each  tree,  by  broods. 


Place  of  entrance. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

First  brood: 

Calyx 

2 
4 

1 
9 

Side 

4 

2 

1 

1 

1 

Stem 

Total 

6 

4 

2 

1 

1 

1 

10 

Second  brood: 

Calyx 

141 

208 
49 

103 
163 
28 

105 
157 
24 

158 

224 

50 

96 
198 
30 

70 
154 
25 

64 
136 
21 

66 

Side... 

121 

Stem 

16 

Total v 

398 

294 

286 

432 

324 

249 

221 

203 

Total  number  of  larvae  and  places  of  entrance  of  fruit  for  each  tree,  by 
broods. 

Total 

for 

plat. 

Percent- 
age of 
larvae  by 
broods* 
entering 
at  calyx, 
side,  and 
stem. 

Total 

larvae, 

first  and 

second 

broods. 

Place  of  entrance. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree 
12. 

Tree 
13. 

First  brood: 

3 

22 

12.00 
88.00 

Side 

Stem 

Total 

25 

Second  brood: 
C&lyz 

74 

147 

13 

877 

1,508 

256 

33.20 

57.10 

9.70 

Bide 

Stem... 

Total 

234 

2,641 

2,666 

ONE-SPRAY   METHOD  FOE   CODLING   MOTH,   ETC, 


123 


Table  III. — Places  of  entrance  into  fruit  by  total  larvx  of  the  codling  math  for  each  tree  of 
each  plat.    Siloam  Springs,  Ark.,  1909 — Continued. 


PLAT  IV.     DEMONSTRATION. 


Total  number  of  larvae  and  places  of  entrance  of  fruit  for  each  tree,  by  broods. 


Place  of  entrance 

Tree  1. 

Tree  2.    Tree  3.    Tree  4.    Tree  5. 

Tree  6. 

Tree  7. 

TreeS. 

First  brood: 

Calyx 

2 

Side 

1 

4 

1 

Stem 

2 

I 

Total                           

1 

6 

1 

4 

Second  brood: 

Calyx 

14 
20 

1 

26 
14 

41 
45 
3 

6 
10 

16 
5 

1 

16 

32 

29 

Side 

7            25 
1              1 

21 

Stem... 

3 

Total 

35 

40 

89 

16 

22 

24 

58 

53 

Total  number  of  larvae  and  places 
bnx 

>f  entrance  of  fruit  for  each  tree,  by 
xls. 

Total 
for 
plat. 

Percent- 
age of 
larvae  by 
broods 
entering 
at  calyx, 
side,  and 
stem. 

Total 

larvae, 

first  and 

second 

broods. 

Place  of  entrance. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree 
12. 

Tree 
13. 

First  brood: 

4 
3 

1 

1 

8 
10 
4 

36.40 
45.40 
18.20 

Side 

Stem 

1 

Total 

7 

2  1            1 

22 



Calyx 

79 
65 
5 

47             " 

328 

247 

16 

55.50 
41.80 
2.70 

Side 

18 

17 

1 

Stem 

Total 

149 

65 

40 

591 

613 

PLAT   V.     UNSPRAYED. 


Total  number  of  larvae  and  places  of  entrance  of  fruit  for  each  tree,  by  broods. 


Place  of  entrance. 

Treel. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

First  brood: 

Calyx 

64 
23 

6 

102 
26 
5 

32 
4 

1 

132 
33 
5 

52 
14 
10 

96 
15 
6 

45 
12 

7 

25 

Side 

7 

Stem 

4 

Total 

93 

133 

37 

170 

76 

117 

64 

36 

Second  brood: 

Calyx 

579 
102 
28 

464 

67 
23 

139 

34 

7 

463 
69 
26 

295 
58 
18 

588 
125 
31 

513 
94 
32 

197 

Side 

49 

Stem 

6 

Total 

709 

554 

180 

558 

371 

744 

639 

252 

124 


DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


Table  III. — Places  of  entrance  into  fruit  by  total  larvx  of  the  codling  moth  for  each  tree 
of  each  plat.     Siloam  Springs,  Ark.,  1909 — Continued. 


PLAT  V.    UNSPRAYED— Continued. 


Number  of  larvae  for  each  tree. 

Total 

for 

plat. 

Percent- 
age of 

larvae  by 
broods 

entering 

at  calyx. 

side,  and 
stem. 

Total 
larvae, 
first  and 
second 
broods. 

Brood  and  place  of  entrance. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree 
12. 

Tree 
13. 

First  brood: 

Calyx 

31 
9 
2 

258 
36 
12 

55 
19 
4 

63 
23 

1 

133 
33 
11 

1,088 

254 

74 

76.84 
17.94 
5.27 

Side 

Stem 

Total 

42 

306 

78 

87 

177 

1,416 

Second  brood: 

Calyx 

489 
98 
28 

458 
89 
11 

535 
81 
29 

398 
94 
29 

353 
96 
15 

5,471 

1,056 

283 

80.34 
15.51 
4.15 

Side 

Stem 

Total 

615 

558 

645 

521 

464 

6,810 

8,226 

In  the  case  of  the  sprayed  plats,  as  would  be  expected,  the  propor- 
tion entering  at  the  calyx  is  greatly  reduced,  and  there  is  a  corre- 
sponding increase  in  the  proportion  entering  the  fruit  at  the  side, 
owing  to  the  lesser  efficiency  of  the  spray  at  the  latter  place.  This 
is  shown  for  each  of  the  plats  in  Table  IV. 

Table  IV. — Places  of  entering  apples,  shown  in  percentages,  of  total  larvae  of  first  and 
second  broods  of  the  codling  moth  combined.     Siloam  Springs,  Ark. ,  1909. 


Percentage  of  larvae  entering— 

Total 

larvae, 

first 

brood. 

Total 
larvae, 
second 
brood. 

Total 
larvae, 

Plat  No. 

Calyx. 

Side. 

Stem. 

Total 

first  and 
second 
broods. 

I.  One-spray  .Bordeaux  nozzles 

III.  One-spray,  Vermorel  nozzles 

IV.  Demonstration 

15.96 
33.01 
54.81 
79.73 

75.38 
57.39 
41.93 
15.93 

8.66 
9.60 
3.26 
4.34 

100.00 
100.00 
100.00 
100.00 

26 

25 

22 

1,416 

3,158 

2,641 

592 

6,810 

3,184 

2,666 

613 

V.  Unsprayed 

8.226 

As  between  the  several  sprayed  plats  there  is  considerable  variation 
in  the  number  of  apples  wormy  at  calyx,  side,  and  stem,  which  is  of 
significance  in  connection  with  the  character  of  the  treatments  given. 
To  compare  these  points  better  Table  V  has  been  prepared. 

Table  V. — Efficiency  of  the  one-spray  and  demonstration  treatments  as  shown  by  the 
percentages  of  wormy  apples.    Siloam  Springs.  Ark.,  1909. 


Plat  No. 

Percentage  of  wormy  apples.** 

Total 

number 

of  wormy 

apples." 

Total 
number 

Calyx. 

Side. 

Stem. 

Total. 

of 

apples. 

I.  One-spray,  Bordeaux  nozzles 

1.18 

3.32 

1.03 

26.85 

5.54 

5.57 

.79 

5.36 

0.64 
.97 
.20 

1.46 

7.24 

9.97 

1.88 

33.26 

3,120 

2,654 

607 

8,120 

43,152 
26,534 

32, 451 

V.  Unsprayed 

24,428 

o  As  some  apples  were  entered  at  more  than  one  place,  the  gums  of  the  percentages  for  calyx,  side, and  item 
slightly  exceed  the  total  percentages  of  wormy  apples. 


ONE-SPRAY   METHOD  FOR  CODLING   MOTH,   ETC. 


125 


A  comparison  of  the  figures  for  the  different  plats  in  Table  V  shows 
as  to  calyx  entrance  for  the  two  broods  about  the  same  degree  of 
protection  in  the  case  of  Plats  I  and  IV,  while  as  between  Plats  I  and 
III,  both  involving  the  one-spray  method,  there  is  a  difference  in 
favor  of  a  coarser  as  against  a  mist  spray  of  1.14  per  cent  of  the  total 
crop.  The  figures  on  side  entrance  show  that  neither  of  the  one-spray 
treatments  afforded  any  protection  to  the  side  of  the  fruit,  while  the 
demonstration  treatment  saved  4.57  per  cent  of  the  crop  by  preventing 
side  entrance.  In  comparing  the  total  efficiency  of  the  different 
treatments,  it  will  be  seen  that  there  was  a  saving  of  26.02  per  cent  of 
the  crop  in  Plat  I,  23.29  per  cent  in  Plat  III,  and  31.38  per  cent  in 
Plat  IV.  The  superiority  of  the  demonstration  treatment  was  mostly 
due  to  the  prevention  of  side  worminess. 

In  order  to  determine  what  effect  the  respective  treatments  might 
have  on  the  proportion  of  fruit  which  dropped  and  that  which 
remained  on  the  trees  until  picking  time  the  following  table  (Table  VI) 
was  prepared  from  the  data  in  the  previous  tables: 


Table  VI. 


-Comparison  of  amounts  of  drop-fruit  during  season  on  the  several  plats. 
Siloam  Springs,  Ark.,  1909. 


Num- 
ber of 
trees. 

Fruit  from  ground. 

Plat  No. 

; 
First  brood.                                     Second  brood. 

Wormy. 

Sound. 

Total. 

Per 

cent 

sound. 

Wormy. 

Sound. 

Total. 

Per 

cent 
sound. 

I 

11 
9 
11 
13 

26 
25 
22 
945 

10,202 

10.228 

99.74 
99.53 
99.74 
89.56 

1,449 

1,249 

240 

5,471 

7,663 
5,997 
5,513 
5,742 

9,112 

7.246 

5,753 

11,213 

84.09 

ni 

5,314       5.339 
8. 970       8-  990 

82.76 

IV 

95.82 

v 

8,109 

9,054 

51.20 

Num- 
ber of 
trees. 

Fruit  from  tree. 

Total  fruit. 

Per 

Plat  No. 

Wormv. !  Sound,  i  Total. 

1 

Per 

cent 

sound. 

Wormy.  |  Sound. 

Total. 

Per 

cent 
sound. 

centage 
of  drop- 
fruit. 

I 

11 
9 
11 
13 

1.645     22.167     23.812 

1,371  ,  12,578     13.949 

345     17.361      17.706 

1.704       2,457       4,161 

! 

93.09 
90.17 
98.05 
59.04 

3,120     40.032 
2,645  !  23,889 

43,152 

2fi  rM- 

92.  76         44.  81 

Ill 

90. 03         47.  42 

IV 

607     31.844  ,  32,451 
8.120     16,308  i  24  428 

98.12         45.43 

V 

66.  76         82. 06 

As  will  be  noted,  the  highest  percentage  of  drop-fruit  was  on  the 
unsprayed  plat,  namely,  82.96,  with  47.42  per  cent  drop-fruit  from 
Plat  III.  Plats  I  and  IV  (the  one-spray  and  demonstration  treat- 
ments) show  a  difference  in  favor  of  the  demonstration  plat  of  only 
0.62  per  cent,  an  amount  practically  negligible.  The  percentage  of 
drop-fruit,  including  fallen  fruit  from  all  causes,  is  shown,  but  it 
should  be  remembered  that  fruit  from  all  plats,  except  the  check, 
was  largely  protected  from  fungous  troubles  by  applications  of  Bor- 
deaux mixture. 


126 


DECIDUOUS   FRUIT  INSECTS   AND  INSECTICIDES. 


THE    PLUM    CUBCULIO. 

Throughout  the  season  the  drop-fruit  and  the  fruit  on  trees  at 
picking  time  from  four  of  the  plats  in  the  Jones  orchard  were  care- 
fully examined  as  to  injury  by  the  plum  curculio.  The  results  of 
examinations  are  given  in  detail  in  Table  VII. 

Table  VII. — Injury  by  plum  curculio  for  entire  season  on  Plats  I,  III,  IV,  and  V, 
sprayed  in  the  codling-moth  experiments.    Siloam  Springs,  Ark.,  1909. 

PLAT  I.     ONE-SPRAY. 


Number  of  punctured  and  sound  fruit,  etc.,  per  tree  in  each  plat. 


Tree  1. 


Tree  2. 


Tree  3. 


Tree  4. 


Tree  5. 


Tree  6. 


Tree  7. 


Tree  8. 


Number  of  punctures 

Number  of  fruit  punctured 

Number  of  sound  fruit 

Number  of  fruit 

Per  cent  free  from  injury. . 


1,979 
1,179 
4,510 
5,689 
79.27 


1,713 

915 

3,898 

4.813 


2,613 
687 
3,109 
3,796 
81.90 


387 
2,363 
2,750 
85.92 


208 
3,238 
3,446 
93.96 


1,012 
532 
3,236 
3,768 
85.88 


638 

370 

2,937 

3,307 

88.81 


1,200 
706 
4.737 
5,443 
87.02 


Number  of  punctured  and  sound  fruit,  etc., 
per  tree  in  each  plat. 

Total  for 
plat. 

Total  per 

cent  fruit 

free  from 

injury. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

Number  of  punctures 

642 

364 

3,280 

3,644 

90.01 

319 

216 

2,436 

2,652 

91.85 

642 

335 

3,560 

3,895 

91.39 

11,709 

5,899 

37,304 

43,203 

Number  of  fruit  punctured 

Number  of  sound  fruit 

Number  of  fruit 

Per  cent  free  from  injury 

86.34 

PLAT  III.     ONE-SPRAY. 


Number  of  punctured  and  sound  fruit  etc.,  per  tree  in  each  plat. 


Tree  1. 


Tree  2. 


Tree  3. 


Tree  4. 


Tree  5. 


Tree  6. 


Tree  7. 


Tree  8. 


Number  of  punctures 

Number  of  fruit  punctured 

Number  of  fruit  free  from  injury 

Number  of  fruit 

Per  cent  free  from  injury 


2,321 
1,051 
3,698 
4,749 
77.86 


721 

349 
2,339 
2.688 
87.01 


919 

533 

2,211 

2,744 

80.57 


788 

368 

2,284 

2.652 

86.12 


560 

358 

1,883 

2.241 

84.02 


1,790 
795 
2,775 
3.570 
77.73 


1,756 
727 
2,154 
2,881 
74.  70 


732 

372 

1.620 

1.992 

81.32 


Number  of  punctured  and  sound  fruit,  etc., 
per  tree  in  each  plat. 

Total  for 

plat. 

Total  per 
cent  fruit 
free  from 
injury. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

1,629 

727 

1,498 

'_'.  220 

11.216 
5,280 

20.457 
25,737 

Number  of  fruit  free  from  injury 

70.48 

1 

ONE-SPBAY   METHOD  FOE  CODLING   MOTH.   ETC. 


127 


Table  VII. — Injury  by  plum  curculio  for  entire  season  on  Plats  I,  III,  IV,  and  V, 
sprayed  in  the  codling-moth  experiments.    Siloam  Springs,  Ark.,  1909 — Continued. 

PLAT  IV.    DEMONSTRATION. 


Number  of  punctured  and  sound  fruit,  etc.,  per  tree  in  each  plat. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

Number  of  punctures 

1,293 
746 
2,790 
3,536 
78.90 

562 

301 

1,589 

1,890 

84.07 

773 

437 

4,639 

5,076 

91.39 

98 

74 

1,591 

1,665 

95.  55 

430 

266 

2,879 

3,145 

91.54 

432 

200 

1,465 

1,665 

87.98 

1,025 
498 
1,998 
2,496 
80.04 

877 

Number  of  fruit  punctured 

467 

Number  of  fruit  free  from  injury 

2,705 
3,172 

Per  cent  free  from  injury 

85.27 

Number  of  punctured  and  sound  fruit,  etc., 
per  tree  in  each  plat. 

Total  for 
plat. 

Total  per 
cent  fruit 
free  from 
injury. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

13, 129 
3,656 
,,135 
1791 
65.43 

254 

140 

1,817 

1,957 

92.84 

1,429 

769 

2,289 

3,058 

74.85 

10,302 

5,554 

26,897 

32,451 

Number  of  fruit  punctured 

Number  of  fruit  free  from  injury 

82.88 

PLAT  V.    UNSPRAYED. 


Number  of  punctured  and  sound  fruit,  etc.,  per  tree  in  each  plat. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

Number  of  puncture , 

6,623 
2,130 
430 
2,560 
16.79 

6,230 
1,595 
106 
1,701 
6.23 

4,331 

948 

47 

995 

4.72 

10,068 

1,522 

16 

1,538 

1.04 

3,372 

999 

207 

1,206 

17.16 

9,527 
2,299 
202 
2,501 
8.07 

14,727 

2,724 

97 

2,821 

3.43 

4,714 

Number  nf  fruit  punctured  . . 

1,070 

Number  of  fruit  free  from  injury 

Number  of  fruit 

86 
1,156 

Per  cent  free  from  injury 

7.43 

Number  of  punctured  and  sound  fruit,  etc., 
per  tree  in  each  plat. 

Total  for 
plat. 

Total  per 
cent  fruit 
free  from 
injury. 

Tree  9. 

Tree  10. 

Tree  11. 

Tree  12. 

Tree  13. 

Number  of  punctures 

6,143 
1,936 
387 
2,323 
16.65 

8,707 

2,117 

141 

2,258 

6.24 

6,921 

1,605 

114 

1,719 

6.63 

5,984 

1,517 

91 

1,608 

5.65 

6,739 
1,750 
310 
2,060 
15.04 

94,086 

22,212 

2,234 

24,446 

Number  of  fruit  punctured 

Number  of  fruit  free  from  injury 

Number  of  fruit.  . . 

Per  cent  free  from  injury 

8.S5 

All  punctures,  whether  egg  or  feeding,  are  classed  together  under 
"  Number  of  punctures."  The  total  percentage  of  fruit  free  from  cur- 
culio injury  includes  fruit  entirely  free  from  feeding  and  egg  punc- 
tures, and  has  no  reference  to  injury  from  other  insects,  as  the  codling 
moth  or  lesser  apple  worm.  Curiously,  in  the  Siloam  Springs  work 
the  one-spray  block  (Plat  I)  shows  the  maximum  percentage  of  fruit 
free  from  curculio  attack,  injury  on  the  demonstration  plat  exceeding 
in  this  regard  that  on  the  one-spray  plat  by  3.46  per  cent.  It  should 
be  noted,  however,  that  Plat  IV  was  adjacent  to  the  unsprayed  block 
(see  fig.  2)  and  there  was  unquestionably  considerable  overflow  of 


128 


DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 


curculio,  as  on  this  latter  the  beetles  were  quite  abundant,  as  shown 
by  the  low  total  percentage  of  uninjured  fruit,  namely,  S.85  per  cent. 
In  view  of  the  habits  of  the  curculio  in  ovipositing  and  feeding  over 
a  considerable  period  (six  to  eight  weeks  or  more),  the  results  from 
the  one-spray  method  are  the  more  surprising,  and  it  would  appear 
that  the  single  treatment  resulted  in  their  almost  complete  destruction. 
In  Table  VIII  are  brought  together  data  showing  the  effects  of  the 
treatments  in  the  control  of  the  three  principal  insect  enemies  of  the 
fruit,  namely,  the  codling  moth,  the  plum  curculio,  and  the  lesser 
apple  worm  (Enarmonia  prunivora  Walsh).  The  value  of  the  one- 
spray  method  is  here  put  to  the  severest  possible  test  so  far  as  con- 
trolling insect  enemies  of  the  fruit  is  concerned.  It  will  be  noted 
that  when  these  three  insects  are  taken  into  account  somewhat  better 
results  were  secured  from  Plat  IV,  which  received  the  demonstration 
treatment,  namely,  81.19  per  cent  sound  fruit,  as  against  79.60  per 
cent  sound  fruit  from  the  one-spray  plat.  The  unsprayed  plat  (V) 
shows  a  very  low  percentage  of  fruit  free  from  injury  by  these  three 
insects,  namely  6.94  per  cent. 


Table  VIII. 


-Effect  of  treatments  on  the  three  principal  fruit  insects  and  total  percentage 
of  sound  fruit.     Siloam  Springs,  Ark.,  1909. 


PLAT  I.     ONE-SPRAY. 


Injured  by  plum  curculio 

Injured  by  codling  moth 

Injured  by  lesser  apple  worm 

Number  injured  apples 

Number  uninjured  apples 

Total  number  apples 


Tree  l. 


1,179 
703 
71 
1,778 
3,911 
5,689 


Tree  2. 


915 

522 

74 

1,403 

3,410 

4,813 


Tree  3. 


687 

419 

41 

1,062 

2,734 

3,796 


Tree  4. 


387 
118 


2,264 
2,750 


Tree  5. 


208 
181 
31 
409 
3,037 
3,446 


Tree  6. 


532 

222 

17 

739 

3,023 

3,762 


Tree  7. 


370 

286 

19 

652 

2,655 

3,307 


Tree  8. 


706 
315 
30 
991 
,452 
,443 


Tree 
9. 

Tree 
10. 

Tree 
11. 

Tree 
12. 

Tree 
13. 

Total 
for 
plat. 

Per  cent 

free  from 

injury. 

Total 

per  cent 

free 

from 

injury. 

364 

110 

10 

473 
3,126 
3,599 

216 

113 

5 

349 

2,303 

2,652 

335 

131 

5 

460 

3,  433 

3,895 

5,899 

3,120 

309 

8,802 

34, 348 

43, 152 

86.34 
92.  74 
99.29 

Injured  by  lesser  apple  worm 

79.60 

PLAT  III.     ONE-SPRAY. 


Injured  by  plum  curculio 

Inland  by  codling  moth 

Injured  by  lesser  apple  worm 

Number  Injured  applea 

Number  uninjured  apples 

Total  number  apples 


Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

1,051 

349 

533 

368 

358 

795 

727 

W7 

291 

2V, 

m 

an 

217 

231 

29 

19 

It 

32 

40 

22 

26 

525 

772 

sua 

684 

l.mo 

919 

2,960 

1,972 

[,846 

l .  567 

2,560 

1,962 

1,749 

3,485 

2,  744 

2.211 

3,570 

2,881 

372 

200 

12 

551 

1,441 

1,992 


ONE-SPRAY   METHOD  FOR  CODLING   MOTH,   ETC. 


129 


Table  VIII. — Effect  of  treatments  on  the  three  principal  fruit  insects  and  total  percentage 
of  sound  fruit.    Siloam  Springs,  Ark.,  1909— Continued. 


PLAT  III.    ONE-SPRAY— Continued. 


Tree 
9. 

Tree 
10. 

Tree 
11. 

Tree 
12. 

Tree 
13. 

Total 
for 
plat. 

Per  cent 
free  from 
injury. 

Total 

per  cent 

free 

from 

injury. 

727 

234 

9 

786 

1,434 

2,220 

5,280 

2,645 

203 

7,416 

19,118 

26,534 

79.48 
90.03 
99.24 

Injured  by  lesser  apple  worm 

72.05 

PLAT  IV.     DEMONSTRATION. 


Injured  by  plum  curculio 

Injured  by  codling  moth 

Injured  by  lesser  apple  worm 

Number  injured  apples 

Number  uninjured  apples 

Total  number  apples 


Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

746 

301 

437 

74 

266 

200 

498 

36 

41 

93 

16 

22 

23 

57 

6 

1 

6 

1 

0 

2 

3 

826 

332 

509 

90 

287 

222 

545 

2,710 

1,558 

4,567 

1.575 

2.858 

1,443 

1,951 

3.536 

1,890 

5,076 

1,665 

3,145 

1,665 

2,496 

Tree  8. 


467 
57 
0 
518 
654 
172 


Tree 
9. 

Tree 
10. 

Tree 
11. 

Tree 
12. 

Tree 
13. 

Total 

for 

plat. 

Per  cent 

free  from 

injury. 

Total 

per  cent 

free 

from 
injury. 

Inj  ured  by  plum  curculio 

1,6.56 
154 
14 
1,761 
3,030 
4,791 

140 

67 

6 

207 

1,750 

1,957 

769 

41 

3 

806 

2,252 

3,058 

5,554 

607 

42 

6,103 

26,348 

32,451 

82.88 
98.12 
99.87 

Injured  by  codling  moth 

Injured  by  lesser  apple  worm 

Number  injured  apples 

Number  uninjured  apples 

81.19 

Total  number  apples 

PLAT  V.    UNSPRAYED. 


Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

2,130 

1,595 

948 

1,522 

999 

2,299 

2,724 

795 

679 

217 

716 

450 

823 

697 

213 

140 

52 

222 

89 

224 

309 

2,250 

1,605 

959 

1,528 

1,072 

2,355 

2,740 

310 

78 

36 

10 

134 

146 

81 

2,560 

1,683 

995 

1,538 

1,206 

2,501 

2,821 

Tree  8. 


Injured  by  plum  curculio 

Injured  by  codling  moth 

Injured  by  lesser  apple  worm 

Number  injured  apples 

Number  uninjured  apples 

Total  number  apples 


1,070 
287 

91 
1,076 

80 
1,156 


Tree 
9. 

Tree 
10. 

Tree 
11. 

Tree 
12. 

Tree 
13. 

Total 

for 

plat. 

Per  cent 
free  from 
injury. 

Total 

per  cent 

free 

from 

injury. 

Injured  by  plum  curculio 

1,936 
652 
120 

1,987 
336 

2,323 

2,117 
859 
218 

2,148 
110 

2,258 

1,605 
709 
139 

1,631 
88 

1,719 

1,517 

592 
174 

1,556 

52 

1,608 

1,750 
644 
77 

1,824 
236 

2,060 

22,212 
8,120 
2,068 

22, 731 
1,697 

24,428 

8.85 
66.75 
91.50 

Injured  by  codling  moth 

Injured  by  lesser  apple  worm 

Number  injured  apples 

Number  uninjured  apples 

6.94 

Total  number  apples 

130 


DECIDUOUS    FKU1T   INSECTS   AND   INSECTICIDE*. 


EXPERIMENTS   IN   VIRGINIA. 

The  experiments  in  Virginia  were  carried  out  in  two  localities, 

namely,  at  Crozet,  in  the  orchard  of  W.  S.  Ballard,  and  at  Mount 
Jackson,  in  the  orchard  of  the  Strathmore  Orchard  Company. 

W.  S.  Ballard's  Orchard. 

W.  S.  Ballard's  orchard  is  located  in  the  eastern  foothills  of  the 
Blue  Ridge  Mountains  and  is  composed  mostly  of  the  Yellow  New- 
town  (Albemarle  Pippin)  variety,  which  sort  was  used  exclusively 


West 
S    S 

S    S 

s  s  s 

s  s  s  s  s 

ssssssss                s 

ssssssssssss 

sssssssss                 s 

D  D    O    O    D    D     D           0          0    0    0    ^ 

00000000000000                2^-^^ 

L     L    L           L     L     L    L     L    L           ODD          D                  ^\^ 

LLLLLLLLL 

ODD 

°  JL°  JL°     ^\ 

DDDDDDDDDD 
D   D    D    D    D    D    D     ODD 

©GO  c  c 

c  (?)  c  c 

d\q)  D\b)o  o             \^ 
&)  d\£a£)       d   d  D  D  DD^, 

1 

D   D    D  D    D  ®®D 

D    D    O    D          D  ©  D 

D    D    D    D    D    D 

ODD          D     D 

/    / 

/     / 

/©©©/  /////// 

/     / 
/     / 

/©©/ 

////////  VI 
////////// 

s  S  s        ssssssssssssss       S  S 

ssssssssssss    s  s  s  s  s  s  s       s 

s  s  s  s  s  ssssssssssssssss 

sssssssssssssssss            S   5 

s  s  s        s   s       ssssssss        s 

ssssssssssssss       s        s 

bowing  arrangement  of  plats  and  trees  in  the  W.  S.  Ballard  orchard  near  Crozet,  Va. 
indicated  by  circles,  the  numbers  agreeing  with  the  numbers  of  trees  in  the  tables. 
Variety,  Yellow  Newtown  (Albemarle  Pippin).    Trees  marked  5  sprayed  by  owner. 

in  the  experiments.  The  location  of  the  trees  sprayed,  with  refer- 
ence  to  adjacent  trees  in  the  orchard,  is  shown  in  figure  35.  The 
surrounding  trees  not  included  in  the  experiment  were  sprayed  by 
owner.  The  size  of  the  trees  and  general  character  of  the  loca- 
t  LOD  are  shown  in  Plate  X,  figure  2. 


ONE-SPRAY  METHOD   FOR  CODDING  MOTH,   ET@. 
THE    CODLING   MOTH. 


131 


The  treatments  given  and   dates   of  applications   are  shown  in 
Table  IX. 


Table  IX.— Dates  of 


for  codling  moth  and    plum  curculio,  one-spray 
method.     Crozet,  Va.,  1909. 


Date  of  application. 

Plat  V. 
( D  emonstration . ) 

Plat  VI. 

(One-spray  method.) 

Plat  VIII. 
(Unsp  rayed.) 

First  application,  April 
27    (after    falling    of 
petals). 

Second  application, 

May  24. 
Third  application,  June 

26. 
Fourth  application, 

July  26-27. 

Not  drenched.    Vermorel  noz- 
zles.   Mist  spray.    Arsenate 
of  lead  2  pounds  to  50  gallons 
Bordeaux  mixture  (2-2-50). 
Pressure  120  to  140  pounds. 

do 

.do 

Drenched  with  arsenate  of  lead 
2  pounds  to  50  gallons  Bor- 
deaux    mixture     (2-2-50). 
Pressure    125-160    pounds. 
Seneca  nozzles.    11  gallons 
per  tree. 

Bordeaux  mixture  only  (2-2- 
50).    Not  drenched, 
.do 

Unsprayed. 

Do. 
Do. 

do 

do 

Do. 

Plat  V  (demonstration)  received  four  applications  in  all,  the  Ver- 
morel nozzle  being  used.  The  effort  was  made  to  spray  thoroughly, 
but  none  of  the  trees  was  drenched.  Plat  VI  (one-spray  method) 
was  thoroughly  drenched,  using  Seneca  nozzles,  applying  an  average 
of  11  gallons  per  tree.  This  plat  received  three  subsequent  appli- 
cations of  Bordeaux  mixture  only,  as  shown  in  the  schedule,  to  pro- 
tect the  fruit  from  possible  infection  by  bitter  rot.  Plat  VIII  was 
left  unsprayed  throughout  the  season  for  purposes  of  comparison. 

The  first  application,  on  April  27,  was  given  just  after  most  of 
the  petals  had  fallen,  and  conditions  were  favorable  for  the  work 
except  that  showers  interrupted  the  spraying  for  about  one  hour. 
At  the  time  of  the  second  application,  May  24,  the  weather  was 
showery,  but  spraying  was  finished  without  serious  interruption. 
The  third  application,  on  June  26,  was  interrupted  near  the  close  of 
the  work  by  rain,  while  the  fourth  application,  on  July  26,  was  made 
under  very  favorable  conditions,  the  weather  being  clear  and  dry. 
Comparatively  little  bitter  rot  developed  during  the  season,  even  on 
the  unsprayed  plat.  A  heavy  hail,  however,  which  occurred  during 
late  June,  badly  injured  the  fruit  and  foliage.  It  was  noticed  that 
the  hail  injury  to  the  fruit  resulted  in  a  much  greater  proportion  of 
codling-moth  larvae  entering  on  the  side,  and  this  fact  must  be  taken 
into  account  in  the  consideration  of  the  results. 

Table  X  gives  the  total  wormy  fruit  and  fruit  free  from  codling- 
moth  injury  for  the  entire  season  for  the  eight  count  trees  of  each 
plat,  the  numbers  of  the  trees  in  the  figure  agreeing  with  those  in 
the  table. 


132 


DECIDUOUS   FRUIT  INSECTS   AND  INSECTICIDES. 


Table  X. — Number  of  sound  and  vorwy  apples  for  each  tree  from  one-spray,  demon- 
stration, and  uns prayed  plats.     Crozet,  Va.,  1909. 


PLAT   V.    DEMONSTRATION. 


Condition  of  fruit. 

Tree  1. 

Tree  2. 

Tree  3. 

Tree  4. 

Tree  5. 

Tree  6. 

Tree  7. 

Tree  8. 

Total 

for 
plats. 

Total 
per 
cent  of 
sound 
fruit. 

Wormy 

90 

712 

115 
1,344 

68 
651 

191 
2,224 

173 

1,859 

49 
1,259 

54 
2,958 

87 
2,243 

827 
13,250 

Sound 

Total 

802 
88.78 

1.459 
92.12 

719 
90.55 

2,415 
92.10 

2,032 
91.49 

1,308 
96.26 

3,012 
98.21 

2,330 
96.27 

14,077 

94. 13 

PLAT   VI.     ONE   SPRAY. 

498 
2,080 

367 
2,166 

627 
4,478 

1,681 
1,150 

445 
2,800 

362 
1,617 

391 
1.650 

462 
1,577 

3,320 
17,518 

Total 

2,578 
80.30 

2,533 
85.52 

5,105 
87.72 

1,318 
87.26 

3,245 
86.29 

1.979 
81.71 

2,041 
80.90 

2,039 
77.35 

20,838 

Per  cent  sound 

84.07 

PLAT  VIII.    UNSPRAYED. 

1,165 
2,258 

1,593 
2,089 

545 
271 

560 
456 

1,641 
1,470 

1,444 
1,544 

1,089 
904 

1,001 
1,206 

9,038 
10, 198 

Total 

3,423 
65.97 

3,682 
56.79 

816  I  1,016 
33.22  1  44.89 

3,111 
47.90 

2,988 
51.68 

1.993 
45.31 

2,207 
54.65 

19,236 

53.02 

Plat  V,  which  received  the  demonstration  treatment,  gave  94.13 
per  cent  fruit  free  from  codling-moth  injury,  as  against  84.07  per  cent 
fruit  free  from  this  insect  on  the  one-spray  plat,  a  difference  in  favor 
of  the  demonstration  treatment  of  10.06  per  cent.  The  check  or 
unsp rayed  plat  (VIII)  shows  53.02  per  cent  fruit  free  from  codling- 
moth  injury,  and  there  is  thus  a  gain  in  sound  fruit  b}^  the  demon- 
stration treatment  of  41.11  per  cent  and  by  the  one-spray  method 
again  of  31.05  per  cent  of  sound  fruit.  As  will  be  seen  from  the 
foregoing  table,  there  were  counted  in  Plats  V,  VI,  and  VIII,  respec- 
tively, 14,077,  20,838,  and  19,236  apples,  a  total  for  all  plats  of 
54,151.  Undoubtedly  the  results  from  the  one-spray  plat  are  less 
favorable  than  would  have  been  the  case  had  there  been  no  hail. 
The  injured  places  on  the  sides  of  the  fruit  permitted  ready  entrance 
of  the  larva?,  as  indicated  on  all  plats  by  the  relatively  high  percentage 
of  larvae  which  entered  the  fruit  on  the  side.  This  condition  is  shown 
in  Table  XI,  which  gives  the  places  of  entrance  of  the  fruit  for  each 
tree  of  each  plat  for  the  total  larva?  of  the  two  broods  throughout 
the  season. 


ONE-SPRAY  METHOD  FOE  CODLING   MOTH,   ETC. 


133 


Table  XI. — Places  of  entrance  of  fruit  by  total  larvae  for  each  tree  of  each  plat.     Crozet, 

Va.,  1909. 

PLAT  V.    DEMONSTRATION. 


Total  number  of  larvae  of  fruit  for  each  tree, 
first  and  second  broods  combined. 

Total 

for 
plats. 

Percent- 
ages of 
larvae  en- 
tering at 
calyx, 
side,  and 
stem. 

Total 

Place  of  entrance. 

Tree 
1. 

Tree 
2. 

Tree 
3. 

Tree 
4. 

Tree 
5. 

Tree 
6. 

Tree 
7. 

Tree 
8. 

ber  of 
larvae. 

First  and  second  broods: 
Calyx 

8 

76 

6 

6 
105 

4 

5 
59 

4 

13 

159 
19 

15 

148 
10 

2 
46 

1 

4 

46 
4 

11 

68 
8 

64 
707 

56 

7.73 

Side 

85. 49    

Stem 

6.78    

1 

Total 

90 

115 

68 

191 

173 

49 

54 

87 

827 

100.00 

827 

PLAT  VI.    ONE  SPRAY. 


First  and  second  broods: 

Calyx 

Side 

Stem 

Total 


35 
443 
20  I 


12 

331 

24 


367 


567 
34 


627 


7 

150 

11 


168 


12 

407 

26 


445 


23 

319 

20 


17 

344 
30 


362       391 


19 
415 
28 


462 


151 

2,976 
193 


3,220 


4.55 

89.64 

5.81 


100.00        3,220 


PLAT  Vm.    UNSPRAYED. 


First  and  second  broods: 
Calvx 

527 
483 

888 
508 

320 
158 

67 

258 

231 

71 

878 
561 
202 

677 
620 
147 

512 
439 
138 

493 

429 

79 

4,553 
3,429 
1,056 

50.38 
37.94 
11.68 

Side 

Stem 

155 

197 

Total - 

1,165    1.593 

545 

560 

1,641 

1,444 

1,089 

1,001 

9,038 

100.00 

9,038 

The  efficiency  of  the  one-spray  and  demonstration  treatments  in 
preventing  worminess  is  shown  in  condensed  form  in  Table  XII. 
Here  it  will  be  seen  that  the  one-spray  method  was  nearly  as  effective 
as  the  demonstration  in  preventing  calyx  entrance,  but  gave  little 
benefit  in  regard  to  side  infestation. 

Table  XII. — Efficiency  of  the  different  treatments  as  shown  by  the  percentages  of  wormy 

apples.     Crozet,  Va.,  1909. 


Percentage  of  wormy  apples. 

Total 
number 

Total 

Plat  No. 

Calyx. 

Side. 

Stem. 

Total. 

wormy   ;   anr,lp~ 
apples.    ,   apples- 

V.  Demonstration 

Per  cent. 

0.45 

0.73 

23.67 

Per  cent. 
5.02 
14.28 
17.82 

Per  cent. 
0.40 
0.92 
5.49 

Per  cent. 
5.87 
15.93 
46.98 

827 
3,320 
9,038 

14,077 

VI.  One-spray 

20,838 

VIII.  Unsprayed 

19,236 

THE   PLUM   CURCULIO. 


The  effect  of  the  treatments  in  the  W.  S.  Ballard  orchard  in  con- 
trolling the  plum  curculio  on  Plats  V,  VI,  and  VIII  is  shown  in  Table 
XIII.  Egg  and  feeding  punctures  are  combined  in  the  table  under 
"No.  punctures." 


134 


DECIDUOUS    PBUTT   INSECTS  AND  INSECTICIDES. 


Ta  n  l  i-  Xlll.  —  Injuryby  plum  curculiofor  entire  season,  Plats  V,  VI,  and  VIII.    Crozet, 

1909. 


PLAT  V.    ] 

DEMONSTRATION. 

Number  of  punctured  and  sound  apples,  etc.,  per 
tree  in  each  plat. 

Total 

for 
plats. 

Total 
percent 
of  fruit 

Tree 
1. 

Tree 
2. 

Tree 
3. 

Tree 
4. 

Tree 
5. 

Tree 
6. 

Tree 

7. 

Tree 

8. 

free  from 
injury. 

157 
115 

802 
85.66 

275 

187 

1,272 

1.459 

163 
103 
616 
719 

524 

345 

2,070 

2,415 

B5.71 

668 

463 

1,569 

2,032 

77.  21 

162 

114 

1,194 

1,308 
91.28 

395 

2ti7 
2,747 
3,014 
91.14 

328 

252 

2,076 

2,328 

89.17 

2,672 

1,846 

12,231 

14,077 

No.  fruit 

87.18   85.67 

86.89 

PLAT  VI.     ONE  SPRAY. 


No.  punctures 

No.  fruit  punctured 

No.  sound  fruit 

No.  fruit 

Per  cent  free  from  injury. 


1,510  !l,290 

'.'i.l   ■     730 
1,617    1,803 
2,578  12,533 

1,2.72    71.17 

2,143 
1,347 
3,758 
5,105 
7:<.  61 

360 

238 

1,080 

1,318 

81.94 

1,095 
719 
2,526 
3,245 
77.84 

647 

405 

1,574 

1,979 

79.53 

775 

521 

1,520 

2.041 

74.96 

823 

511 

1,528 

2,039 

74.93 

8,644 

5,432 

15,406 

20,838 

73.93 


PLAT  VIII.    UNSPRAYED. 


No.  punctures 

No.  fruit  punctured 

No.  sound  fruit 

No.  fruit 

Per  cent  free  from  injury. 


2.  740 
1,256 

2,168 
3,423 
63.30 

2,571 
1,571 
2,111 
3,682 
57.33 

705 
437 
379 
816 
57.33 

962 

531 

485 

1,016 

46.44 

2,490 
1,415 
1,696 
3.111 
47.73 

1,939 
1,193 
1,795 
2,988 
60.00 

1,865 
1,098 
882 
1,980 
44.54 

2,300 
1,285 
806 
2,091 
38.54 

15,578 
8,785 
10,322 
19, 107 

54.02 


The  percentage  of  fruit  uninjured  by  the  curculio  in  the  demonstra- 
tion block,  86.89  per  cent,  shows  a  gain  over  that  of  the  one-spray 
plat,  73.93  per  cent,  of  12.96  per  cent,  and  the  gain  in  percentage  of 
uninjured  fruit  on  the  demonstration  over  the  unsprayed  plat  is 
32.87. 

Orchard  of  Strathmore  Orchard  Company. 


The  orchard  of  the  Strathmore  Orchard  Company  is  located  near 
Mount  Jackson,  in  the  Shenandoah  Valley  of  Virginia.  The  size  of 
the  trees  and  general  appearance  of  the  orchard  are  indicated  in 
Plato  XI,  figure  1.  The  location  of  the  trees  under  experiment  with 
respect  to  the  rest  of  the  orchard  is  shown  in  figure  36.  All  trees  not 
in  t  ho  experiment  were  sprayed  by  the  owners.  The  treatments  given 
and  dates  of  application  are  stated  in  Table  XIV. 


Table  XIV. 


I)<tl,s  of  applications  for  codling  moth  and  plum   curculio,   otic-spray 
method.      Mount  .Tackson,   Va.,  1909. 


I  application. 


PlatXfll.    (Demonstration.) 


Plat  XV.  (One-spray  method.) 


Plat  XVII. 
(Unsprayed.) 


No)  drenched.  Vermorel noz- 
zles. Mm  spray.  Ar 
of  lead,  2  pounds  to  50 
gallons  Bordeaux  mixture 
(l-i  50).  Pre8Borel20to  1 10 
pounds.  4.7  gallone  per  tree. 

Not  drenched.  Vermorel  noz- 
zles. Mist  spray.  Arsenate 
of    lead,  2    pounds  to  50 

Villous   Bordeaux    mixture 
.0). 
Third  application,  July    do 


First  applicai 

tiling  of 

petals). 


I  application  .May 


Drenched    with    arsenate    of 
I,  2  pounds  to  50  gallons 

water.  Preasnre  175  pounds. 

Beneca  nozzles.    8.1  gallons 

per  tree. 

Bordeaux  mixture  only  (2-2- 
50).    Not  drenched. 


Unsprayed. 


Do. 


.do. 


Do. 


Bui.  80,  Part  VII,  Revised,  Bireaj  of  Entomology,  U.  S.  Dept.  oc  Agriculture. 


Plate  XI. 


Fig.  1.— View  in  Orchard  of  the  Strathmore  Orchard  Company,  near  Mount 
Jackson,  Va.    'Original. 


Fig.  2.— View  in  the  E.  H.  House  Orchard,  near  Saugatuck,  Mich.    (Original.) 


ONE-SFKAY  METHOD  FOR  CODLING   MOTH,   ETC. 


135 


The  demonstration  plat  (XIII)  received  in  all  three  treatments  of  a 
combined  Bordeaux  mixture  and  arsenate  of  lead  spray.  Plat  XV 
(one-spray  method)  received  only  one  arsenate  of  lead  treatment  just 
after  the  falling  of  the  petals,  but  two  additional  applications  of 
Bordeaux  mixture  were  given  to  protect  the  fruit  and  foliage  from 
fungous  diseases.  Plat  XVII  was  left  unsprayed  throughout.  The 
Ben  Davis  variety  of  apple  was  used  entirely  in  the  experiments. 


s  s  s 

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t 
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s  s  s  s 

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s  s 

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S    S    S    S    S    SfSSSSSSSSSSSSSS    SSSSSSSSS 

S  5  s  $  s   sssssssssssss   ssssssssssss 

£esf 


Fig.  36.— Diagram  showing  arrangement  of  plats  and  trees  in  the  orchard  of  the  Strathmore  Orchard  Co., 
near  Mount  Jackson,  Va.  Trees  marked  S  sprayed  by  the  owner;  trees  marked  L  used  for  experiments 
with  lime-sulphur  wash.    Circles  indicate  count  trees,  the  numbers  agreeing  with  those  in  the  tables. 

THE    CODLING   MOTH. 

The  results  of  the  respective  treatments  in  the  control  of  the  codling 
moth  are  shown  in  Table  XV. 

Table  XV. — Number  of  sound  and  wormy  apples  for  each  tree  from  one-spray,  demon- 
stration, and  unsprayed  plats.     Mount  Jackson,  Va.,  1909. 


PLAT 

XIII. 

DEMONSTRATION. 

Condition  of  fruit. 

Tree 
1. 

Tree 
2. 

Tree 
3. 

Tree 
4. 

Tree 
5. 

Tree 
6. 

Tree 
7. 

Tree 
8. 

Total 

for 
plats. 

Total 
per  cent 
sound. 

Wormy 

200 
1,666 

136 
1,172 

155 
3,311 

83 
625 

173 
1,494 

168 
3,618 

119 
944 

150 

2,278 

1,184 
15, 108 

Sound 

Total 

1,866 
89.29 

1,308 
S9.61 

3,466 
95.53 

708 
88.28 

1,667 
89.69 

3,786 
95.57 

1,063 

88.81 

2,428 
93.83 

16,292 

Per  cent  sound 

92.74 

PLAT  XV.    ONE  SPRAY. 

Wormy 

250 

3,577 

253 

3,404 

86 
589 

186 
730 

250       219 
1,429  |3,261 

122 

847 

257 
4,042 

1,623 

17,879 

Sound 

Total 

3,827 
93.49 

3,657 
93.09 

675 

87.26 

916 
79.70 

1,679   3,480 
85.12   93.71 

969 
87.41 

4,299 
94.03 

19,502 

Per  cent  sound 

91.68 

PLAT  XVII.    UNSPRAYED. 

Wormy 

1,913 
2,013 

1,425 
1,684 

865 
S65 

983 
524 

1,538 
1,651 

1,792  2,027 
2,361  |3,094 

1,247 
1,548 

11,790 
13,840 

Sound 

Total 

3,926 

3.109 
54.17 

1.830 
52.19 

1,507 
34.78 

3,189 
51.78 

4,153   5,121 
56.86  !fin.42 

2,795 
55.42 

25,630 

Per  cent  sound 

51.23 

54  00 

30490°— Bull.  80—12- 


-10 


136 


DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 


The  influence  of  the  treatments  on  the  places  of  entrance  of  fruit 
by  the  larvae  of  the  first  and  second  broods  combined  for  the  respective 
plats  is  shown  in  Table  XVI. 


Table  XVI. — Places  of  entrance  of  fruit  by  total  larvae  for  each  tree  of  each  plat. 

Jackson,  Va.,  1909. 

PLAT  XIII.    DEMONSTRATION. 

Mount 

Total  number  of  larvse  of  fruit  for  each  tree,  first 
and  second  broods  combined. 

Total 

for 
plats. 

Percent- 
ages of 
larvae 
entering 
at  calyx, 
side,  and 
stem. 

Total 

Place  of  entrance. 

Tree 

Tree 
2. 

Tree 
3. 

Tree 
4. 

Tree 
5. 

Tree 
6. 

Tree 
7. 

Tree 
8. 

ber  of 
larvae. 

First  and  second  broods: 
Calyx 

32 

154 

14 

14 
111 

11 

15 

122 

18 

16 

58 

9 

20 

136 

17 

26 

125 

17 

15 
92 
12 

24 

116 

10 

162 

914 
108 

13.68 
77.20 
9.12 

Side 

Stem 

Total 

200 

136 

155 

83 

173 

168 

119 

150 

1,184 

100.00 

1,184 

PLAT  XV.    ONE  SPRAY. 

First  and  second  broods: 
Calyx 

13 
190 
47 

32 
193 

28 

6 
74 
6 

16 
143 
27 

25 

173 

52 

19 

183 

17 

18 
91 
13 

17 

214 

26 

146 

1,261 

216 

8.99 
77.70 
13.31 

Side 

Stem... 

Total 

250 

253 

86 

186 

250  I     219 

122 

257 

1,623 

100.00 

1,623 

PLAT  XVII.    UNSPRAYED. 

First  and  second  broods: 
Calyx 

1,466 
332 
115 

1,063 

265 

97 

699 
119 
47 

762 
141 
80 

1,232 
203 
103 

1,377 
295 
120 

1,584 
353 

90 

969 
209 
69 

9,152 

1,917 

721 

77.62 
16.26 
6.12 

Side 

Stem 

Total 

1,913 

1,425 

865 

983 

1,538   1.792 

2,027 

1.247 

11,790 

100.00 

11,790 

For  more  ready  comparison  of  the  efficiency  of  the  treatments, 
Table  XVII  is  given,  from  which  it  will  be  seen  that  the  demonstra- 
tion and  the  one-spray  treatments  were  about  equally  effective  in 
protecting  the  calyx  and  that  neither  was  satisfactory  in  controlling 
worms  entering  the  side.  The  difference  in  total  efficiency  between 
the  demonstration  and  the  one-spray  plats  is  quite  small,  namely, 
1.06  per  cent  in  favor  of  the  former.  The  unsprayed  trees  show  46 
per  cent  of  wormy  fruit,  so  there  is  a  total  saving  of  3S.44  per  cent 
of  the  crop  by  the  demonstration  treatment  and  37.68  per  cent  by 
the  one-spray. 

Tablk  XVII. — Efficiency  of  the  one-spray  and  demonstration  treatments  as  shown  by 
the  percentages  of  wormy  apples.     }fonnt  Jackson,  Va.,  1909. 


Plat  No. 


Percentage  of 

wormy  apples. 

Total 
number 

of  wormy 
apples. 

Calyx. 

Side. 

Stem. 

Total. 

P.ct. 
0.99 

86.71 

P.  ct. 
5.61 
6.  if, 

P.ct. 
0.66 
l.ll 
2.81 

P.ct. 

7.:v. 

46.00 

1.1M 

1,623 

1 1 .  720 

Total 
number 

of  apples. 


XII r  (demonstration) 

XV   mno-spniy) 

XVII  tunspravnl). . . 


16,222 

19.502 
25,630 


ONE-SPRAY   METHOD  FOB  CODDING   MOTH,   ETC. 


137 


THE   PLUM   CUECULIO. 

The  plum  curculio  proved  to  be  unusually  destructive  in  the 
Strathmore  orchard,  which  had  not  been  plowed  for  at  least  two 
years  and  had  grown  up  in  grass  and  sod.  The  results  of  the  respec- 
tive treatments  in  the  control  of  this  insect  are  showndn  Table  XVIII, 
and  as  will  be  noted  the  percentage  of  fruit  free  from  curculio  injury 
is  in  all  cases  comparatively  low.  Nevertheless  the  one-spray  treat- 
ment shows  a  gain  of  17.08  per  cent  of  fruit  free  from  injury  over  the 
demonstration  treatment,  and  a  gain  of  30.67  per  cent  of  fruit  free 
from  injury  over  the  unsprayed  trees.  The  location  of  the  trees  in 
the  respective  plats  does  not  indicate  a  more  favorable  place  as 
regards  liability  to  curculio  injury  for  the  one-spray  block  and  the 
notably  higher  benefit  of  the  single  treatment  in  the  control  of  the 
curculio  on  this  plat  is  not  understood. 

Table  XVIII. — Injury  by  the  plum  curculio  for  entire  season,  Plats  XIII,  XV,  and 
XVII.     Mount  Jackson,  Va.,  1909. 


PLAT  XIII. 

DEMONSTRATION. 

Number  of  punctured  and  sound  apples,  etc.,  per 
tree  in  each  plat. 

Total 

for 
plat. 

Total 
per  cent 
fruit  free 

from 
injury. 

Tree 
1. 

Tree 
2. 

Tree 
3. 

Tree 
4. 

Tree 
5. 

Tree 
6. 

Tree 
7. 

Tree 
8. 

No.  punctures 

2.961 

1,367 

499 

2,391 
755 
553 

3,067 
1,631 
1,835 
3,466 
52.94 

932 
441 

267 
708 

3,013 

1,257 

410 

1,667 

4.040 
2,197 
1,589 
3,786 
41.97 

1,486 

612 

451 

1,063 

42.42 

2,869 
1,382 
1.047 
2,429 
43.10 

20, 759 
9,642 
6.651 

16,293 

No.  fruit  punctured 

Kn.  finnrifi  frnit. ........ 

1,866 
26.79 

1.308 
42.27 

Per  cent  free  from  injury 

33.71 

24.58 

40.82 

PLAT  XV.     ONE  SPRAY. 


No.  punctures 

No.  fruit  punctured 

No.  sound  fruit 

No.  fruit 

Per  cent  free  from  injury . 


2,782 

1,800 

633 

1,032 

1.449 

2,159 

987 

3.153 

13,995 

1,507 

1,788 

303 

494 

754 

1.212 

447 

1,735 

8,240  - 

2.320 

1,869 

372 

495 

925 

2.268 

522 

2.564 

11,335 

3.827 

3.657 

675 

989 

1.679 

3,480 

969 

4.299 

19.575 

60.62 

51.10 

55.11 

50.15 

55.09 

65.17 

53.86 

59.64 

57.90 


PLAT  XVII.    UNSPRAYED. 


No.  punctures 

No.  fruit  punctured 

No.  sound  fruit 

No.  fruit 

Per  cent  free  from  injury . 


7,336 

4,497 

2,212 

2,888 

5.030 

6,122 

8,779 

4.904 

41,768  ' 

3,186 

2,226 

1,079 

1,226 

2,399 

2,823 

3,611 

2,107 

18,657 

740 

883 

761 

282 

790 

1.330 

1.510 

688 

6.984 

|3,926 

3,109 

1,840 

1,508 

3,189 

4.153 

5,121 

2,795 

25,641 

18.84 

28.40 

41.35 

18.61 

24.77 

32.04 

29.46 

24.61 

27.23 


EXPERIMENTS  IN  MICHIGAN. 

The  experiments  in  Michigan  were  carried  out  in  the  vicinity  of 
Saugatuck,  in  the  orchard  of  Mr.  E.  H.  House.  The  location  of  the 
plats  in  the  orchard  and  of  the  count  trees  in  the  respective  plats 
is  shown  in  figure  37.  The  size  of  the  trees  is  illustrated  in  Plate 
XI,  figure  2.  This  orchard  included  trees  of  the  Wagener,  Ben  Davis, 
and  Baldwin  varieties,  and  an  equal  number  of  trees  of  each  variety 
was  used  for  counts  in  the  respective  plats.  As  in  the  work  else- 
where, all  drop-fruit  during  the  season,  as  well  as  that  from  the  trees 


138 


DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 


at  picking  time,  was  taken  into  account  and  classified  as  to  injury  or 
otherwise.  Also  the  work  of  the  two  broods  of  the  codling  moth  was 
carefully  separated  by  removing  from  the  trees  at  the  period  of 
maximum  maturation  of  the  first-brood  larvae  all  fruit  injured  by  the 
first  brood,  thus  eliminating  entirely  from  later  counts  first-brood 
work.  The  infested  apples,  however,  were  placed  on  the  ground 
under  the  respective  trees,  so  that  development  of  second-brood 
larvae  would  be  in  no  wise  interfered  with. 


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Fig.  37.— Diagram  illustrating  arrangement  of  plats  and  position  of  trees  in  the  E.  H.  House  orchard,  near 
Bangatncr,  Midi.:  D,  Ben  Davis;  B,  Baldwin;  W ,  Wagener.  Count  trees  are  indicated  by  circles,  the 
numbers  agreeing  with  those  in  the  tables. 

The  treatments  given  and  dates  of  application  are  indicated  in 
Table  XIX. 

Table  XIX. — Dates  of  applications  for  the  codling  moth  and  plum  carculio,  one-spray 
method.     SaugatueJ:,Micft.,  1909. 


Date  of  application. 

Plat  I. 
(Unsprayed.) 

Plat  II.    (Demonstration.) 

Plat  III.    (One-spray  method.) 

ipplicstion  (before 
emu  opened  I , 
It*y20-2L 

■  n  '1   application, 
June  8  0,  liter  falling 
of  pet*]*. 

1  liir.l  application,  June 
21  22. 

Fourth  application, 
August  7-9. 

Dneprayed 

do 

do 

do 

Not  drenched.  Vermore]  noz- 
zles. Mist  sprav.  Bordeaux 
mixture  1 1 

Not  drenched.   Vermore]  noa- 

zles.     Mist  sprav.     Arsenate 
of  lead,  2  pounds  to  50  gal- 
lons     Bordeaux      mixture 
(4-4-50).          Pressure,     125 
pounds. 
do 

do 

Drenched.  Bordeaux  nozzles. 
Coarse  sprav.  Bordeaux  mix- 
ture 

Drenched.  Bordeaux  nozzles. 
( osise  spray.  Arsenate  of 
lead,  1  pound  to  50  gallons 
water.  Pressure,  175  to  200 
pounds. 

Bordeaux  mixture  onlv  (4-4- 
50).  June  10-11  and  again 
June  21-23. 

Bordeaux  mixture  onlv  (4-4- 
50). 

ONE-SPRAY   METHOD  FOE   CODLING    MOTH.   ETC. 


139 


Plat  I  was  left  unsprayed  for  purposes  of  comparison.  Plat  II 
(demonstration  block)  received  four  applications  in  all,  the  first  before 
blooming  but  after  cluster  buds  had  opened,  to  protect  the  fruit  from 
apple  scab,  which  during  some  seasons  in  the  lake  region  is  very 
troublesome.  Plat  III  (one-spray  block)  received  the  first  scab  treat- 
ment of  Bordeaux  mixture  only  and  an  additional  treatment  with 
arsenate  of  lead  only  at  the  rate  of  1  pound  to  50  gallons  water  imme- 
diately after  the  falling  of  the  petals.  This  treatment  was  immediately 
followed  by  an  application  of  Bordeaux  mixture  to  prevent  scab 
infection,  as  it  was  considered  unsafe  to  apply  the  fungicide  so 
excessively  as  the  one-spray  method  required  in  the  use  of  the  arsen- 
ical. Plat  III  received  two  subsequent  applications  of  Bordeaux 
mixture  only,  as  shown  in  the  schedule  of  applications,  to  further 
insure  freedom  from  apple  scab. 

THE    CODLING    MOTH. 

The  percentages  of  wormy  and  sound  fruit  for  the  respective  plats 
for  the  season  are  shown  in  Table  XX,  and  the  numbers  of  trees  in 
the  table  agree  with  those  in  the  diagram  of  the  orchard  (fig.  37). 

Table  XX. — Sound  and  uormy  fruit  jrorn  unsprayed,  demonstration,  and  one-spray 
plats.     Saugatuck,  Mich.,  1909. 

PLAT  I.     UNSPRAYED. 


Condition  of  fruit. 


Tree 
1. 


Tree 
3. 


Tree 
4. 


Tree 


Tree 
9. 


Tree 
10. 


Tree 
13. 


Wormy 

663 
3.996 

752 
5,033  ! 

605 

2.947 

166 

1.340 

946 

1,805 

1.207  ! 
2.676 

416 

Sound 

2.213 

Total 

4.659 
85.76 

5.785 
87.00  | 

3.552 
82.96 

1,506 
88.97 

2.751 
65.61 

3,883 

68.91 

2.629 

Per  cent  sound 

84  17 

Condition  of  fruit. 

Tree       Tree 
16.          20. 

Tree 
21. 

Tree 
26. 

Tree 
33. 

Total  1  Total 
for      per  cent 
plat,     sound. 

Wormv 

889  !       651 
1.926       2.632 

404 
1,276 

1.041 
2,321 

669 

8.409    

Sound 

1.301     29,466    

Total 

Per  cent  sound 

2.815       3.2S.3 
68.  14       8a  17 

1,680 
75.95 

3.362  1     1.970  1  37,875 
69.03       66.03  1 

"*77.*79 

PLAT  II.    DEMONSTRATION. 


Condition  of  fruit. 

Tree 

101. 

Tree 
102. 

Tree 
105. 

Tree 
106. 

Tree 
108. 

Tree 
115. 

Tree 
117. 

Wormv 

120 

1,505 

122 
1,643 

48 
2,112 

75 
1,775 

96 
5.623 

72 
3,950 

15 

Sound 

5,781 

Total 

1,625 
92.61 

1.765 
9a  08 

2.160 
97.77 

1.850 
95.94 

5.719 
98.32 

4.022 
98.20 

5,796 

Per  cent  sound 

99.74 

140 


DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


Table  XX. — Sound  and  wormy  fruit  from  unsprayed,  demonstration,  and  one-spray 
plats.    Saugatuck,  Mich.,  1909 — Continued. 

PLATE  II.    DEMONSTRATION-Continued. 


Condition  of  fruit. 

Tree 
118. 

Tree 
127. 

Tree 
132. 

Tree 
135. 

Tree 
136. 

Total 

for 

plat. 

Total 
percent 
sound. 

Wormy 

25 

5,188 

91 
4,336 

13 
4,285 

245 
3,978 

76 
1,644 

998 
41,820 

Sound 

Total 

5,213 
99.52 

4,427 
97.94 

4,298 
99.69 

4,223 
94.19 

1,720 
95.58 

42,818 

Per  cent  sound 

97.66 

PLAT  III.    ONE  SPRAY. 

Condition  of  fruit. 

Tree 
224. 

Tree 
225. 

Tree 
232. 

Tree 
236. 

Tree 
237. 

Tree 
238. 

Tree 
239. 

Wormy 

500 
3,113 

103 
4,602 

396 
3,061 

343 

2,753 

118 
2,779 

41 
3,510 

62 

Sound 

3,062 

Total 

3,613 
86.16 

4,705 
97.95 

3,457 
88.54 

3,096 
88.92 

2,897 
95.92 

3,551 
98.84 

3,124 

Per  cent  sound 

9a  01 

Condition  of  fruit. 

Tree 
244. 

Tree 
245. 

Tree 
246. 

Tree 
249. 

Tree 
252. 

Tree 
266. 

Total 

for 

plat. 

Total 

percent 

sound. 

Wormy 

452 
4,107 

340 
4,001 

165 
2,743 

62 

3,381 

46 
1,092 

110 
1,925 

2,738 
40,129 

Sound 

Total 

4,559 
90.08 

4,341 
92.16 

2,908 
94.32 

3.443 
98.19 

1,138 
95.95 

2,035 
94.59 

42,867 

Per  cent  sound 

9i  61 

In  the  foregoing  table  the  demonstration  plat  shows  an  increase  of 
sound  fruit  over  the  one-spray  method  of  4.05  per  cent  and  over  the 
unsprayed  plat  of  19.87  per  cent.  There  was  less  injury  on  the 
unsprayed  trees  than  usual  for  that  section,  due  to  the  small  size  of 
the  second  brood.  Only  13  per  cent  of  the  first-brood  larvae  from 
bands  transformed  to  moths. 

The  effect  of  the  treatments  on  the  places  of  entrance  of  fruit  by 
larvae  of  the  first  and  second  broods  is  shown  in  Table  XXI. 

Table  XXI. — Places  of  entrance  of  fruit  by  total  larvx  for  each  tree  of  each  plat.    Sauga- 
tuck, Mich.,  1909. 

PLAT  I.    UNSPRAYED. 


Brood  and  place  of  entrance. 

Number  of  larvae  for  each  troe. 

Tree  1. 

Tree  3. 

Tree  4. 

Tree  7. 

Tree  9. 

Tree  10. 

Tree  13. 

Tree  16. 

First  brood: 

133 
39 
5 

206 
24 
8 

172 

25 

0 

68 

10 
0 

316 
28 

7 

257 
28 
6 

168 
17 
4 

214 

Bfdfl   

40 

Shin 

5 

Total 

177 

238 

197  |          75 

351 

291 

189 

259 

Second  brood: 

(alvx 

•J77 

213 

16 

717 
Mfl 

9 

274 
155 

51 
39 
2 

279 

319 

19 

316 

360 

30 

140 

87 

7 

357 

Side 

306 

Mm...    . 

11 

Total 

506 

530 

444             92 

617 

706 

234 

674 

OXE-SPBAY   METHOD   FOR  CODLING   MOTH,   ETC. 


141 


Table  XXI. — Places  of  entrance  of  fruit  by  total  larvxfor  each  tree  of  each  plat.    Sauga- 
tuck,  Mich.,  1909— Continued. 

PLATE  I.    UNSPRAYED— Continued. 


Number  of  larvae  for  each  tree. 

Percentage 
oflarvee 
entering. 

Total  larvae 

Brood  and  place  of  entrance. 

Tree  20. 

Tree  21. 

Tree  26. 

Tree  33. 

Total 

for 

plat. 

of  first 

and  second 

broods. 

First  brood: 

Calvx    

176 
17 
4 

129 

21 

5 

442 
68 
13 

266 

59 

9 

2,544 

376 

66 

85.20 
12.59 
2.21 

Side..  .                     

Stem...                     

Total.                         

197 

155 

523 

234 

2.986 

.  econd  brood: 

Calvx 

Side 

208           105 

240           151 

IS               6 

290 
231 
21 

183 
181 

18 

2,752 

2,531 

172 

50.45 

4&  40 

3.15 

Stem 

Total 

466 

262 

542 

382 

5,455 

8,441 

PLAT  II.    DEMONSTRATION. 


Number  of  larvae  for  each  tree. 

Brood  and  place  of  entrance. 

Tree 
101. 

Tree 
102. 

Tree 
105. 

Tree 
106. 

Tree 
108. 

Tree 
115. 

Tree 
117. 

Tree 
118. 

First  brood: 

Calvx 

1 
14 

12 

5 

8 

1 

10 
5 

2 
5 

2 

Side 

9 

U 
1 

4 

Stem 

Total 

9 

13 

15 

12 

14 

15 

7 

6 

Second  brood: 

Calvx 

2 
95 

1 

Side 

146 

155 

41 

81 

73 

8 

19 

Stem 

Total 

146 

155 

41              81 

97 

73 

8 

20 

Brood  and  place  of  entrance. 

Number  of  larvae  for  each  tree. 

Percentage 
of  larvae 
entering. 

Total  larvae 

Tree 
127. 

Tree 
132. 

Tree 
135. 

Tree 
136. 

Total 
for 
plat. 

of  first 

and  second 

broods. 

First  brood: 

Calyx 

8 
7 

1 

1 

...... 

2 

11 

31 

115 
2 

2a  95 

77.70 

Las 

Side 

Stem 

Total 

15 

2 

27 

13 

148 

Second  brood: 

Calyx 

1 
95 

1 

ii' 

1 

320 

1 

1 

93 

6 

1,137 

2 

.■J       .... 

Side 

99.30  !   . 

Stem 

.18 

Total 

97 

li 

322 

94 

1,145  ! 1               1-293 

142 


DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 


Table  XXI. — Place*  of  entrance  of  fruit  by  total  larvxfor  each  tree  of  each  plat.    8auga~ 
tuck,  Mich.,  1909— Continued. 


PLAT  III.    ONE  SPRAY. 


Number  of  larvae  for  each  tree. 

Brood  and  place  of  entrance. 

Tree 
224. 

Tree 
225. 

Tree 
232. 

Tree 
236. 

Tree 
237. 

Tree 
238. 

Tree 
239. 

Tree 
244. 

First  brood: 

Calyx 

5 

86 
2 

3 
6 

'"is 

2 
24 

1 

1 

2 
5 

1 
2 

3 

Side 

31 

Stem 

Total 

93 

10 

15 

27 

7 

7 

3 

34 

Second  brood: 

Calyx 

4 

356 

9 

1 

141 

6 
416 

4 

370 

4 

1 

161 

1 
43 

1 
75 

4 

Side 

492 

Stem 

2 

Total 

369 

142 

422 

378 

162 

44 

76 

498 

Number  of  larvae  for  each  tree. 

Per- 
centage 
of  larvae 
enter- 
ing. 

Total 
larvae  of 

Brood  and  place  of  entrance. 

Tree 
245. 

Tree 
246. 

Tree 
249. 

Tree 
252. 

Tree 
266. 

Total 

for 

plat. 

first 

and 
second 
broods. 

First  brood: 

Calyx 

2 
40 

1 

13 
2 

1 

6 

20 

245 

6 

7.38 

90.41 

2.21 

Side 

1 

9 

Stem 

Total 

42 

16 

7 

1 

9 

271 

Second  brood: 

Calyx 

9 

297 

13 

"'176' 
4 

4 
67 

52' 

2 
131 

37 

2,777 

33 

1.30 

97.54 

1.16 

Side 

Stem... 

Total 

319 

180 

71 

52 

134 

2,847 

3,118 

A  study  of  the  percentages  of  larvae  of  the  respective  broods  enter- 
ing the  calyx,  side,  and  stem  ends  of  the  fruit  for  each  plat,  as  shown 
in  Table  XXI,  presents  some  points  of  interest.  On  all  plats  a 
greater  percentage  of  larvae  of  the  first  brood  entered  at  the  calyx 
than  was  true  of  larvae  of  the  second  brood.  Thus,  on  the  un- 
sprayed  plat  (I),  85.20  per  cent  of  the  first-brood  larvae  entered  at 
calyx  as  against  50.45  per  cent  of  second-brood  larvae.  On  Plat  II 
(demonstration)  20.95  per  cent  of  first-brood  larvae  entered  at  calyx 
end  as  compared  with  0.52  per  cent  of  second-brood  larvae,  while  on 
Plat  III  (one  spray)  7.38  per  cent  of  first-brood  larvae  entered  at  calyx 
and  1.30  per  cent  of  second-brood  larvae  entered  at  this  place. 

Attention  should  also  be  called  to  the  ratio  of  increase  of  larvae 
between  the  first  and  second  broods.  On  Plat  I  (unsprayed)  for 
every  larva  of  the  first  brood  there  were  1.82  second-brood  larvae, 
whereas  on  Plat  II  (demonstration)  and  Plat  III  (one  spray)  for  each 
larva  of  the  first  brood  there  were  7.7  and  10.5,  respectively,  of  the 
second  brood. 


ONE-SPRAY   METHOD  FOE  CODLING   MOTH.   ETC. 


143 


Similar  comparison  may  also  be  made  from  the  data  from  Arkansas. 
Thus,  on  the  unsprayed  plat  (V)  for  each  first-brood  larva  there  were 
4.8  second-brood  larvae.  On  Plat  III  (one  spray)  for  each  larva  of 
the  first  brood  there  were  105.6  larvae  of  the  second  brood.  Plat  I 
(one-spray  method)  shows  for  each  first-brood  larva  121.5  second- 
brood  larvae. 

To  show  the  comparative  efficiency  of  the  demonstation  and  one- 
spray  treatments  in  preventing  infestation  at  calyx,  side,  and  stem, 
Table  XXII  is  presented. 

Table  XXII. — Efficiency  of  the  one-spray  and  demonstration  treatments  as  shown  by 
the  percentage  oj  wormy  apples.     Saugatuck,  Mich.,  1909. 


Plat  No. 


Percentage  of  wormy  apples.^ 


Calyx.         Side.  Stem. 


Total. 


Total         ~  +oI 
apples.*   °fapples. 


I.  Unsprayed 

II.  Demonstration. 
III.  Onespray 


Per  cent. 

13.98 

.09 

.13 


Per  cent. 
7.67 
2.92 
7.05 


Per  cent. 

0.62 

.01 


Per  cent. 
22.20 
2.33 
6.36 


8.409 

998 

2,738 


37.875 
42,818 
42,867 


a  Each  entrance  was  counted  in  determining  the  percentages  for  calyx,  side,  and  stem,  so  that  the  sum 
of  these  percentages  exceeds  the  total  percentage  of  wormy  fruit. 

It  is  here  seen  that  the  two  methods  of  spraying  were  about  equally 
effective  in  preventing  entrance  at  the  calyx,  and  that  the  one-spray 
method  had  practically  no  effect  upon  side  entrance.  The  demon- 
stration treatment  saved  a  total  of  4.03  per  cent  of  the  crop  more 
than  the  one-spray,  practically  all  of  this  saving  being  due  to  the  pre- 
vention of  side  entrance.  But,  as  in  all  the  other  experiments,  the 
demonstration  treatment  failed  to  reduce  side  entrance  to  anything 
like  the  same  degree  that  calyx  entrance  was  prevented. 

THE    PLUM    CURCTTLIO. 

The  effects  of  the  applications  of  sprays  on  the  plum  curculio  in  the 
E.  H.  House  orchard  are  shown  in  Table  XXIII. 


Table  XXIII. — Injury  by  the  plum  curculio  /or  entire  season,  Plats  I,  II,  and  III. 

Saugatuck,  Mich.,  1909. 


PLAT  I.     UNSPRAYED. 


Number  of  punctured  and  sound  apples,  etc.,  per  tree  in 
each  plat. 

Tree 
1. 

Tree 
3. 

Tree        Tree 
4.             7. 

Tree 
9. 

Tree 
10. 

Tree 
13. 

No.  punctures 

1,452 

422 

506  1        505 

1,078 

756 

372 

3.511 

3.883 

90.42 

141 

No.  fruit  punctured 

866           214 
3.793        5-571 

220           241 

480 

56 

No.  sound  fruit 

3,332       1,265       2.271 

2,573 

No.  fruit 

Per  cent  free  from  injury 

4.659 
81-41 

5,785 
96.30 

3.552       1.506 
93.81       83.99 

2,751 
82.55 

2,629 

97.87 

144 


DECIDUOUS   FRUIT  INSECTS  AND  INSECTICIDES. 


Table   XXIIT. — Injury  by  the.  plain  curculio  for  entire  season,  Plats  I,  II,  and  III. 
Saugatuck,  Mich.,  1909 — Continued. 

PLAT  I.    UNSPRAYED— Continued. 


Number  of  punctured  and  sound  apples,  etc., 
per  tree  in  each  plat. 

Total 

per  cent 

fruit 

Tree 
16. 

Tree 
20. 

Tree 
21. 

Tree 
26. 

Tree      Total 
33.      forplat. 

free 
from 
injury. 

No.  punetures 

1,108 
454 
2,361 
2,815 
83.87 

883 

426 

2,857 

3,283 

86.96 

530 

329 

1.351 

1,680 

80.42 

1,265 
644 
2,718 
3,362 
80.85 

1,197  1    9,843  ' 

462       4,764    

1,508     33-11 

No.  fruit  punctured 

No.  sound  fruit 

1,970 
76.55 

37,875    

ST    lO 

PLAT  II.     DEMONSTRATION. 


Number  of  punctured  and  sound  apples,  etc.,  per  tree  in 
each  plat. 


Tree 
101. 


Tree 
102. 


Tree 
105. 


Tree 
106. 


Tree 
108. 


Tree 
115. 


Tree 
117. 


No.  punctures 

No.  fruit  punctured 

No.  sound  fruit 

No.  fruit 

Per  cent  free  from  injury 


24 

11 

1,614 

1,625 

99.38 


37 

13 

1,752 

1,765 

99.26 


32 

15 

2,145 

2,160 

99.31 


128 

60 

1,790 

1,850 

96.76 


169 

61 

5,658 

5,719 

98.93 


12 

5 
4,017 
4.022 


102 

02 

5,734 

5,796 


Number  of  punctured  and  sound  apples,  etc., 
per  tree  in  each  plat. 

Total 

per  cent 

fruit 

Tree 
118. 

Tree 
127. 

Tree 
132. 

Tree 
135. 

Tree 
136. 

Total 
for  plat. 

free 

from 

injury. 

112 

32 

5,181 

5,213 

99.39 

89 
50 

4,377 
4,427 
98.87 

139 

58 

4,240 

4,298 

98.65 

398 

153 

4,070 

4,223 

96.38 

10 
3 

1,717 
1,720 
99.83 

1,252 

523 

42,295 

42,818 

No.  sound  fruit 

No.  fmit 

9S.  77 

PLAT  III.     ONE  SPRAY. 


Number  of  punctured  and  sound  apples, 
each  plat. 

etc.,  per  tree  in 

Tree 
224. 

Tree 
225. 

Tree 
232. 

Tree 
236. 

Tree 
237. 

Tree 
238. 

Tree 
239. 

1,015 

374 

3,239 

3,613 
89.  92 

278 

117 

4,588 

4,706 

97.51 

10S 

35 

3,422 

3,457 

98.99 

198 

85 

3,011 

3,096 

97.25 

64 
30 

2.S67 
2,897 
98.96 

67 

33 

3,518 

3,551 

99.07 

4.'. 

19 

3,105 

3,124 

Per  cent  free  from"  injury 

99.39 

Number  of  punctured  and  sound  apples,  etc.,  per 
tree  in  each  plat. 

Total 

per  cent 

fruit 

Tree 
244. 

Tree 

245. 

Tree 

Tree 
249. 

Tree 
252. 

Tree 
266. 

Total 
for  plat. 

free 
from 

injury. 

228 

255 
102 

4,341 

238 

91 

1,817 

194 
49 

3. -lit!) 

98.75 

42 
20 

1,118 

06.24 

143 

40 

1,995 

2,035 

98.03 

2,875 

1,054 

41.813 

42,867 

So.  (roll  iHMictured 

N.j.  fruit 

'  [!".•«•  from  injury 

97.54 

ONE-SPRAY   METHOD   FOR  CODLING   MOTH.   ETC. 


145 


The  plum  curculio,  it  will  also  be  noted,  was  not  especially  destruc- 
tive at  Saugatuck,  Mich.,  during  the  season  of  1909,  the  unsprayed 
trees  showing  87.42  per  cent  of  fruit  free  from  injury.  Nevertheless 
the  demonstration  and  one-spray  plats  show  a  fair  benefit,  but  the 
difference  in  the  amount  of  fruit  free  from  injury  between  these  two 
plats,  namely,  1.23  per  cent,  is  not  important. 

SUMMARY  STATEMENT  OF  RESULTS. 

For  the  purpose  of  more  ready  comparison,  the  percentages  of  fruit 
free  from  codling-moth  and  plum-curculio  injury  on  the  one-spray, 
demonstration,  and  unsprayed  plats,  from  the  several  localities,  are 
tabulated  in  Table  XXIV.  The  average  percentage  of  fruit  free  from 
these  insects  for  the  four  orchards  gives  for  the  one-spray  method 
91.46  per  cent  as  against  96.57  per  cent  for  the  demonstration  treat- 
ment, a  gain  in  favor  of  the  latter  of  5. 1 1  per  cent.  Comparing  the  final 
average  of  percentage  of  fruit  free  from  the  plum  curculio,  there  is  seen 
to  be  a  gain  in  favor  of  the  demonstration  treatment  of  6.27  per  cent. 

Table  XXIV. — Percentages  of  fruit  free  from  injury  by  the  codling  moth  and  plum  cur- 
culio on  one-spray,  demonstration,  and  unsprayed  plats  in  Arkansas,  Virginia,  and 
Michigan,  in  1909. 


Locality. 

Codling  moth. 

Plum  curculio. 

One 

spray. 

Demon- 
stration. 

Un- 
sprayed. 

One 

spray. 

Demon-  '       Un- 
stration.    sprayed. 

Siloam  Springs,  Ark 

92.76 
84.07 
91.68 
93.61 

98.12 
94.13 
92.74 
97.66 

66.74 
53.02 
54.00 
77.79 

86.34 
73.93 
57.90 
97.54 

82.88 
86.89 
40.82 
98.77 

8.85 

Crozet,  Va 

54.02 

Mount  Jackson ,  Va 

27.23 

Saugatuck,  Mich 

87.42 

Average  of  four  localities 

91.46 

96.57 

65.14 

77.10 

83.37 

49.17 

Table  XXV  presents  in  comparison  the  effect  of  treatments  for  the 
four  orchards  in  reducing  the  number  of  wormy  apples.  The  table 
shows,  besides  the  total  efficiency,  the  protection  afforded  to  each 
of  the  different  parts  of  the  apple.  From  the  averages  of  the  four 
localities  it  will  be  seen  that  approximately  two-thirds  of  the  total 
larvae  on  the  unsprayed  plat  entered  through  the  calyx,  while  on 
the  sprayed  plats  over  three-fourths  of  the  worms  entered  the  fruit 
by  way  of  the  side.  This  shows  the  very  much  greater  efflcienc}^ 
of  the  poison  in  the  calyx  than  of  that  on  the  side  of  the  fruit  and 
emphasizes  the  twofold  advantage  of  a  thorough  poisoning  of  the 
calyx,  as  there  it  is  that  the  spray  gives  the  greatest  protection 
against  the  greatest  number  of  larvae.  A  comparison  of  the  effects 
of  the  one-spray  and  demonstration  treatments  on  the  percentage 
of  apples  wormy  at  the  calyx  shows  about  an  equal  degree  of  pro- 
tection by  the  two  methods,  the  average  for  the  demonstration 
treatment  being  slightly  the  better.  As  to  side  entrance,  the  one- 
spray  gave  little  improvement  over  the  unsprayed  condition,  while 
the  demonstration  showed  a  considerable  reduction.  Both  methods 
were  effective  in  reducing  entrance  at  the  stem  end,  the  demonstra- 
tion somewhat  the  more  so. 


146 


DECIDUOUS   FRUIT  INSECTS   AND   INSECTICIDES. 


Txble  XXV. — Efficiency  of  the  one-spray  and  demonstration  treatments,  as  shown  by 
the  percentages  of  wormy  apple*,  Arkansas,  Virginia,  and  Michigan,  1909. 


Percentage  of 

ivormy  apples. 

Calyx. 

Side. 

Stem. 

Total. 

Locality. 

d 

.2 

d 

d 

o 

a 

>> 

2 

T3 

>» 

2 

-o 

>> 

2 

T3 

>> 

2 

■g 

2 
a, 

H 

1 

2 

i 

2 

03 
E 

ft 

§ 

C3 

2 

ft 

§ 

| 

I 

S 

B 

p. 
a 

S 
3 

a 

s 

1 

1 

a 

i 

i 

a 

S 

B 

f 

o 

ft 

£> 

o 

p 

P 

O 

Q 

t3 

O 

0 

P 

P.ct. 

P.ct. 

P.ct. 

P.ct. 

P.ct. 

P.ct. 

P.ct. 

P.ct. 

p.ct. 

P.c*. 

P.ct. 

P.c*. 

Siloam  Springs,  Ark 

1.18 

1.03 

2G.85 

5.54 

0.79 

5.36 

0.64 

0.20 

1.46 

7.24 

1.88 

33.26 

Crozet,  Va 

.73 
.75 

.45 
.99 

23.67 
35.71 

14.28 
6.46 

5.02 
5.61 

17.82 
7.48 

.92 
1.11 

.40 
.66 

5.49 
2.81 

15.93 
8.32 

5.87 
7.26 

46.98 

Mount  Jackson,  Va 

46.00 

Saugatuck,  Mich. a 

.13 

.09 

13.98 

7.05 

2.92 

7.67 

.09 

.01 

.62 

6.36 

2.33 

22.20 

Average 

.68 

.57 

23.85 

7.64 

2.87 

8.92 

.59 

.18 

2.21 

8.55 

3.42 

34.80 

a  The  figures  under  calyx,  side,  and  stem  for  Saugatuck  are  based  on  the  number  of  entrance  holes  in- 
stead of  the  number  of  apples  entered. 

CONCLUSIONS. 

From  the  data  presented,  covering  one  season's  work  in  three 
States,  it  appears  that  very  satisfactory  results  may  be  obtained  by 
the  one-spray  method,  in  so  far  as  the  control  of  the  codling  moth 
and  plum  curculio  is  concerned,  although  further  experimentation 
will  be  necessary  before  final  conclusions  can  be  reached.  Sight  must 
not  be  lost,  however,  of  the  fact  of  the  necessity,  under  eastern  condi- 
tions, of  making  applications  of  Bordeaux  mixture  or  other  fungicide 
for  the  control  of  fungous  diseases;  so  that  in  effect  the  one-spray 
method  under  present  practices  can  not  be  recommended  to  orchard- 
ists  in  regions  where  fungous  troubles,  such  as  apple  scab,  apple 
fruit  blotch,  bitter  rot,  and  leaf-spot  affections  require  treatment. 

The  results,  however,  show  the  great  importance  of  very  thorough 
spraying  to  fill  the  calyx  cups  with  poison.  The  efficiency  of  the 
spray  at  this  point  is  much  greater  than  at  any  other  part  of  the 
apple.  This,  taken  in  connection  with  the  fact  that  the  majority  of 
the  larvae  seek  the  calyx  as  a  point  of  entrance,  makes  the  filling 
of  the  calyx  of  prime  importance.  Although  the  importance  of 
accomplishing  this  has  long  been  recognized  by  entomologists  and 
fruit  growers,  it  would  appear  that  this  work  has  not  been  done 
with  sufficient  thoroughness  in  the  past,  and  eastern  apple  growers 
could  certainly  with  great  profit  give  more  attention  to  thorough- 
ness in  the  first  spraying  for  the  codling  moth,  immediately  after 
the  falling  of  the  petals.  The  russeting  of  the  fruit  following  such 
drenching  applications  of  Bordeaux  mixture,  in  which  the  arsenical  has 
been  generally  applied,  may  doubtless  be  avoided  by  the  substitution 
as  B  fungicide  of  dilute  or  self-boiled  lime-sulphur  wash,  as  shown  to 
be  feasible  by  Mr.  W.  M.  Scott,  of  the  Bureau  of  Plant  Industry. 


U.  S.  D.  A.,  B.  E.  Bui.  80,  Part  VHI.  D.  F.  1. 1.,  November  2;.  1910. 

PAPERS  ON  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 


TESTS  OF  SPRAYS  AGAINST  THE  EUROPEAN  FRUIT 
LECANIUM  AND  THE  EUROPEAN  PEAR  SCALE. 

By  P.  R.  Jones. 
Engaged  in  Deciduous  Fruit  Insect  Investigations. 

INTRODUCTION. 

Attention  appears  to  have  been  first  called  in  California  to  the 
brown  apricot  scale  by  Mr.  Alex.  Craw°  in  1891,  at  which  time  the 
insect  was  described  by  him  under  the  name  Lecanium  amneniacum. 
The  investigations  of  Mr.  J.  G.  Sanders6  while  an  agent  of  this  Bureau, 
however,  have  unmistakably  shown  that  the  brown  apricot  scale 
of  California  is  identical  with  Lecanium  corni  Bouche,  known  in 
Europe  since  1844,  which  Mr.  Sanders  has  appropriately  named 
"the  European  fruit  Lecanium." 

The  European  pear  scale  (Epidiaspis  pyricola  Del  Guer.)  was  first 
recorded  as  occurring  in  the  United  States  by  Prof.  J.  H.  Corn- 
stock0  in  1883,  from  Sacramento,  Cal.,  under  the  preoccupied  name 
Diaspis  ostreseformis.  Since  their  introduction  these  two  scale 
pests  have  been  the  subject  of  considerable  attention  on  account 
of  their  injuries,  and  at  the  present  time  in  the  Santa  Clara  Valley 
are  by  far  the  most  important  scale  insects  with  which  orchardists 
have  to  contend.  The  European  fruit  Lecanium  is  now  especially 
abundant  and  the  copious  honeydew  excreted  by  the  scales  upon 
the  leaves  and  fruit,  with  the  accompanying  sooty  fungus,  leaves 
the  fruit  in  an  unsightly  condition  for  market. 

In  connection  with  other  work  in  the  deciduous  fruit  insect  inves- 
tigations of  the  Bureau  of  Entomology,  carried  on  at  the  laboratory 
at  San  Jose,  Cal.,  experiments  have  been  made  to  determine  an 
effective  treatment  for  both  of  these  insects,  with  the  results  recorded 
in  the  following  pages.  The  work  during  1908  was  carried  out  by 
Messrs.  Dudley  Moulton  and  Chas.  T.  Paine. 

oRept.  Cal.  State  Bd.  Hort.,  p.  12,  1891. 

bJourn.  Econ.  Ent.,  vol.  2,  p.  443,  1909. 

c2d  Rept.  Ent.  Dept.  Cornell  Univ.,  p.  94,  1883. 

147 


148  DECIDUOUS   FRUIT   INSECTS  AND  INSECTICIDES. 

THE  EUROPEAN   FRUIT  LECANIUM. 

(Lecanium  corni  Bouch6.) 

APPEARANCE    OF   THE    INSECT. 

The  insect  heretofore  generally  known  as  the  brown  apricot  scale 
belongs  to  the  subfamily  of  scale  insects,  the  Lecaniinae,  being  naked 
but  with  hardened  derm,  and  differs  from  the  San  Jose  scale  and 
European  pear  scale  in  that  the  horny  covering  of  the  full  grown  scale 
is  .1  part  of  the  body  of  the  insect,  while  in  the  case  of  the  other  species 
mentioned  the  body  is  protected  by  a  waxy  covering  made  up  from 
secretions  and  the  molted  skins  of  the  larvae. 

The  adult  female  of  the  European  fruit  Lecanium  is  about  one- 
eighth  to  three-sixteenths  of  an  inch  long,  three-thirty-seconds  to 
one-eighth  of  an  inch  wide,  and  about  one-eighth  of  an  inch  high, 
3rellowish  in  color,  marked  with  black.  The  older  scales  are  shiny, 
oval,  convex,  and  often  covered  with  a  mealy  pruinose  deposit  (see 
PI.  XII,  fig.  1). 

PLAN   OF    WORK   AND    METHOD   OF   ASCERTAINING    RESULTS. 

In  the  winter  of  1909  an  infested  orchard  near  San  Jose,  Cal.,  was 
selected  and  divided  into  9  different  plats  of  14  trees  each.  Eight 
plats  were  used  for  trying  out  various  sprays,  and  the  ninth  plat  was 
left  unsprayed  for  a  check. 

It  was  planned  to  examine  a  number  of  twigs  at  intervals  of  two 
da}^s,  two  weeks,  five  weeks,  three  months,  and  ten  months  from 
date  of  spraying  for  proportion  of  live  and  dead  scales;  also,  to  take 
into  account  the  action  of  the  different  washes  on  the  trees  and  to 
examine  the  fruit  as  to  freedom  from  the  sooty  fungus.  The  effect 
of  the  sprays  upon  the  growth  of  lichens  on  the  trunk  and  limbs 
was  also  to  be  noted.  Such  a  number  of  examinations  was  considered 
necessary  as  some  of  the  sprays  were  immediate  in  their  action  while 
others  acted  over  a  longer  period. 

APPLICATION    OF    SPRAYS. 

All  of  the  plats  were  treated  February  18  with  the  sprays  indi- 
cated below,  using  a  single  bent-disk  nozzle  (with  one-eighth  inch  hole 
in  disk)  on  each  rod,  the  pressure  being  maintained  at  about  200 
pounds  by  means  of  B  gasoline-power  outfit.  At  this  pressure  the 
lichens  were  thoroughly  soaked.  From  4  to  5  gallons  of  liquid  were 
used  p<t  tree  and  the  work  was  very  thoroughly  done. 

SPRATS    USED   AND    KETHOD   OF   PREPARATION. 

Plat  I,  6  per  cent  <!isti  Hate-oil  emulsion. — This  was  made  after  the 
formula  given  in  Bulletin  80,  Part  IV.  Bureau  of  Entomology.  A 
concentrated  emulsion  was  made  by  dissolving  30  pounds  of  fish- 


Bui.  80,  Part  VIII,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  XII. 


Fig.  1.— The  European  Fruit  Lecanium  (Lecanium  corni  Bouche)  on  Pecan. 

(Original.) 


Fig.  2.— The  European  Pear  Scale  (Epidiaspis  pyricola  Del  Guer.)  on  Pear. 

(Original.) 


EUROPEAN   FRUIT  LECAXIUM   AND    PEAR    SCALE.  149 

oil  soap  in  12  gallons  of  hot  water  and  pouring  the  mixture  into  the 
spray  tank  with  20  gallons  of  distillate  oil  (28°  Baum6).  The 
mixture  was  then  thoroughly  agitated  and  run  through  the  nozzles 
into  a  barrel  at  about  150  to  180  pounds  pressure,  giving  a  thick, 
creamy  emulsion  of  about  55  per  cent  strength  of  oil.  A  powerful 
agitation,  such  as  obtained  by  driving  the  liquid  through  nozzles 
or  the  relief  valve  at  a  high  pressure,  seems  to  be  the  most  important 
factor  in  obtaining  a  stable  emulsion.  The  formula  used  for  the 
stock  emulsion  was: 

Hot  water gallons. .  12 

Fish-oil  soap pounds. .  30 

Distillate  oil  (28°  Baume) gallons. .  20 

The  fish-oil  soap  was  made  as  follows : 

Water gallons. .     6 

Lye pounds. .     2 

Fish  oil gallons. .     1£ 

The  soap  ingredients  were  boiled  for  about  two  hours  and  gave 
about  40  pounds  of  soap. 

The  6  per  cent  distillate  emulsion  was  made  by  taking  about  5 \ 
gallons  of  the  concentrated  emulsion  and  44^  gallons  of  water. 
One  pound  of  caustic  soda  was  used  to  soften  the  water. 

Plat  2,  5  per  cent  distillate-oil  emulsion  and  caustic  soda. — This  was 
prepared  by  using  4J  gallons  of  the  concentrated  or  stock  emulsion,  5 
pounds  of  caustic  soda,  and  45i  gallons  of  water  to  make  50  gallons  of 
spray. 

PlatS,  6  per  cent  distillate-oil  mechanical  emulsion. — Made  by  using  3 
gallons  of  distillate  oil  (28°  Baume),  1  pound  of  caustic  soda,  and  47 
gallons  of  water  to  make  50  gallons  of  the  liquid.  This  was  agitated 
violently  for  about  five  minutes  before  being  applied. 

Plat  4,  caustic  soda. — Six  pounds  of  caustic  soda  were  used  to  50 
gallons  of  water. 

Plat  5,  12  per  cent  crude-oil  emulsion. — The  formula  used  for  this 
emulsion  was — 


Fish-oil  soap pounds. 

Lye do . . . 

Crude  oil gallons. 

Water do... 


5 
1 

6 
43 


This  formula  makes  50  gallons  of  liquid.  The  soap  was  dissolved 
in  about  10  gallons  of  hot  water;  the  soap  water  was  then  poured  into 
the  tank  and  the  rest  of  the  43  gallons  added;  then  the  1  pound  of 
lye  was  added  and  the  crude  oil  poured  in  slowly  while  the  mixture 
was  being  agitated.  More  water  should  never  be  added  after  the  oil 
has  been  poured  in.  The  crude  oil  used  was  pure  "Coalinga  special" 
crude  petroleum  16°  to  22°  Baume,  with  an  asphalt  base. 


150 


DECIDUOUS   FRUIT   INSECTS  AND   INSECTICIDES. 


Plat  6,  resin-soda  wash. — The  following  formula  was  used: 

Resin pounds. .  10 

Caustic  soda do 3 

Fish  oil do. . . .  1$ 

Water gallons. .  50 

The  resin  was  broken  into  small  lumps  and  together  with  the  caustic 
soda  placed  in  a  kettle  with  10  gallons  of  water.  The  mixture  was 
then  boiled  for  about  half  an  hour,  and  while  boiling  1|  pounds  of  fish 
oil  were  added;  it  was  then  poured  into  the  tank  and  diluted  with 
sufficient  water  to  make  50  gallons  of  the  wash. 

Plat  7,  commercial  lime-sulphur  solution  (1-8). — Six  and  one-fourth 
gallons  of  the  concentrated  lime-sulphur  solution  and  43|  gallons  of 
water  were  used  to  make  50  gallons  of  spray. 

Plat  8,  borax. — Ten  pounds  of  borax  were  used  in  50  gallons  of  water. 

Plat  9. — For  purposes  of  comparison  this  plat  was  left  unsprayed. 

The  respective  treatments  and  results  of  same  are  shown  in  the 
following  table: 

Table  I. — Results  of  spraying  for  the  European  fruit  Lecanium,  San  Jose,  Cal.,  1909. 


Plat 
No. 


Treatment. 


First  examina- 
tion, Feb.  22, 1909. 


Z4 


58 


S73 


to 


Second  examina- 
tion, Mar.  6,  1909. 


II 


C3   03 

3 


if 


Distillate-oil  emulsion 

Distillate-oil  emulsion  and  caustic  soda. . 
Distillate-oil  emulsion,  mechanical  mix- 
ture   

Caustic  soda 

Crude-oil  emulsion 

Resin  wash 

Commercial  lime-sulphur  wash  No.  1 

Borax 

Check 


Feb.  18 
..do... 


.do... 
.do... 
.do... 
.do... 
.do... 
.do... 
.do... 


305 
428 

467 
100 
90 
180 
400 
200 
325 


304 


465 
96 
90 
180 
400 
200 
14 


99 
98 
100 
100 
100 
100 
4 


926 
647 

216 
194 
122 

30 
252 

64 


ti4U 

118 
179 

78 
21 
17 
38 

71 


Plat 
No. 


Treatment. 


Distillate-oil  emulsion 

Distillate-oil    emulsion    md 

Ic  soda. 

Ion,   me- 
chanical mixture. 

Caustic  soda 

Crude-Oil  emulsion 

•  tab 

Comm<  I  nl])  h  u  r 

No.  l. 






Third  examina- 
tion, Mar.  26, 1909. 


290 

21'.) 
94 

107 


290 

23 1 

219 

61 
94 
64 

II 

31 
24 


— 


LOO 
100 

11)0 
01 

100 
16 

17 


Fourth  examinaton, 
July  1, 1909. 


Scales  all  (loud;  lichens 

dead. 
....do , 


.do. 


....do 

....do 

A  few  live  scales 

A     numl>cr     of     live 

•  .  all  alive; 
Qourishing. 


Fifth  examination, 
Dec.  13, 1909. 


Scales  all  dead;  lichens 
dead. 
Do. 

Do. 

Do. 
Do. 
Do. 

A      number     of     live 
scales:  lichens  dead. 
Do. 

Scales  nearly  all  alive; 
lichens  flourish  in  tr. 


EUROPEAN  FRUIT  LECANIUM  AND   PEAR   SCALE.  151 

RESULTS. 

It  will  be  seen  from  Table  I  that  nearly  all  of  the  washes  showed 
lower  percentages  of  dead  scales  at  the  time  of  the  second  examina- 
tion than  at  the  first,  third,  fourth,  and  fifth  examinations.  The 
first  five  washes  gave  excellent  results  in  the  percentage  of  scales 
killed,  and  cleaned  the  trees  from  lichens. 

Lime-sulphur  wash  and  borax  gave  apparently  excellent  results 
upon  the  first  examination,  but  later  examinations  proved  these 
washes  to  be  of  little  value,  and  the  trees  at  the  end  of  the  season 
appeared  little  better  than  the  unsprayed  trees. 

The  fruit  (12  tons)  from  the  8  sprayed  blocks  was  free  from  the 
smut  fungus,  while  that  from  the  unsprayed  trees  was  quite  black  in 
appearance.  Caustic  soda,  borax,  lime-sulphur,  and  the  resin  wash 
were  all  caustic  and  immediate  in  their  action  on  the  insects.  The 
distillate  sprays  were  prompt  in  their  action,  but  not  so  much  so  as  the 
former.  The  crude-petroleum  sprays  gave  more  of  a  smothering 
effect,  and  were  slower,  their  action  extending  over  a  long  period. 

None  of  the  washes  injured  the  trees  seriously,  but  the  caustic 
soda,  resin,  lime-sulphur,  and  borax  sprays  blackened  the  buds  and 
hardened  the  bark  to  some  extent. 

The*  distillate  and  crude-oil  sprays  did  not  injure  the  buds  or  the 
bark  of  the  trees  in  the  least,  although  some  of  the  buds  were  very 
far  advanced  at  the  time  of  application. 

It  was  noted  during  the  summer  that  the  distillate  and  crude-oil 
emulsions  seemed  to  possess  fungicidal  properties.  On  sprayed 
apricots  and  prunes,  the  foliage  w*as  dark  and  healthy  and  of  much 
better  color  than  on  the  unsprayed  blocks. 

THE  EUROPEAN  PEAR  SCALE. 

(Epidiaspis  pyricola  Del  Guer.) 
APPEARANCE    OF    INSECT   AND   EXTENT    OF    INJURY.0 

The  European  fruit  scale,  or,  as  it  is  commonly  known  in  California, 
the  Italian  pear  scale,  closely  resembles  to  the  naked  eye  the  San 
Jose  scale  (Aspidiotus  perniciosus  Comst.),  but  can  be  readily  dis- 
tinguished from  this  species  by  the  form  of  the  male  scale  which  is  a 
great  deal  longer  and  carinated.     (See  PI.  XII,  fig.  2.) 

Furthermore,  they  can  be  separated  by  the  manner  of  working. 
The  European  pear  scale,  in  California,  so  far  as  the  writer  has  observed, 

a  Comparatively  little  has  been  written  in  an  economic  way  concerning  this  insect, 
either  in  this  country  or  in  Europe.  The  writer  has  been  unable  to  find  an  account 
of  its  life  history;  probably  because  it  has  never  proved  so  serious  as  some  of  the 
other  scales  injurious  to  fruit  trees.  Attention,  however,  is  called  to  an  article  on 
the  synonymy  of  the  species  by  C.  L.  Marlatt  in  Entomological  News,  November, 
1900,  p.  590. 

30490°— Bull.  80—12 11 


152  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 

works  only  under  cover  of  the  lichens  on  the  trunk  and  larger  limbs, 
and  apparently  does  not  work  on  the  twigs  or  younger  branches  as 
does  the  San  Jose4  scale.  While  the  European  pear  scale  is  not  so  serious 
a  pest  to  fruit  trees  as  is  the  San  Jose  scale,  nevertheless  its  manner 
of  working  under  lichens  causes  it  to  he  neglected  by  fruit  growers 
until  the  trees  are  badly  infested,  with  consequent  loss  in  vitality. 

SPRAYING    EXPERIMENTS    IX    1908. 

PLAN    OF    WORK    AND    MANNER    OF   APPLICATION. 

An  orchard  badly  infested  with  the  European  pear  scale  (see  PL 
XIII)  was  selected  in  February,  1908,  and  divided  into  16  plats  of 
6  to  16  trees  each.  It  was  planned  to  examine  a  large  number 
of  scales  in  the  laboratory  from  the  treated  trees  of  each  plat,  and  a 
like  number  from  the  unsprayed,  or  check,  trees,  and  also  to  make 
field  examinations  as  to  the  effect  of  the  sprays  on  the  scales,  on  the 
lichens,  and  on  the  trees* 

The  applications  of  sprays  were  made  February  18,  19,  and  20  on 
plats  1  to  12;  and  March  3,  on  plats  13  to  16.  A  strong  hand-pump 
tank  outfit  and  also  a  barrel  pump  w^ere  used.  No  pressure  gauge 
was  on  the  pumps,  but  pressure  was  probably  not  more  than  60  to 
75  pounds.     Vermorel  nozzles  were  used. 

SPRAYS    USED   AND    METHOD    OF   PREPARATION. 

Plat  1,  lime-sulphur  wash. — This  was  made  after  the  same  formula 
described  for  the  European  fruit  Lecanium. 

Plat  2,  commercial  lime-sulphur  solution  No.  1. — The  stock  solu- 
tion Avas  used  at  the  rate  of  1  part  to  9  parts  of  water. 

Plat  3,  commercial  lime-sulphur  solution  No.  2. — This  spray,  of 
different  brand,  was  used  at  same  strength  as  preceding. 

Plat  4,  commercial  4  per  cent  distillate-oil  emulsion. — This  was  used 
as  follows: 

Distillate-oil  emulsion gallons..     3£ 

Caustic  soda pound. .       \ 

Water gallons. .  50 

Plat  5a,  home-made  10  per  cent  distillate-oil  emulsion. — This  was 
made  according  to  the  following  formula: 

Boiling  water gallons. .  5 

Fish-oil  soap pounds. .  2 

Caustic  soda do £ 

I  distillate  (28°  Baum6) gallons. .  5 

"When  the  water  started  to  boil,  the  caustic  soda  was  added;  then 
the  soap,  and  finally  the  oil.  The  whole  mixture  was  then  forced 
through  a  pump  to  emulsify  it;  it  was  then  poured  into  the  barrel 
and  necessary  water  (40  gallons)  to  make  50  gallons  of  the  spray  was 

added. 


Bui.  80,  Part  VIII,  Bureau  of  Entomology,  U.  S.  Dept.  of  Agriculture. 


Plate  XIII. 


EUROPEAN   FRUIT  LECAXIUM  AND   PEAR    SCALE.  153 

A  perfect  emulsion  was  not  formed,  as  some  of  the  oil  came  to  the 
top. 

Plat  ob.  10  per  cent  distillate-oil  emulsion. — This  was  made  as 
follows : 

Boiling  water gallons. .     5 

Fish-oil  soap pounds. .     H 

Distillate    28°  Baumel gallons. .     5 

Water  (40  gallons)  was  added  to  make  50  gallons  of  the  mixture. 
The  emulsion  was  imperfect. 

Plat  6,  creosote-oil  emulsion. — This  is  a  commercial  preparation  and 
recommended  to  be  used  at  the  rate  of  1  part  to  20  parts  of  water, 
but  was  used  3  parts  to  20  of  water. 

Plat  7a,  home-made  10  per  cent  creosote-oil  emulsion. — The  following 
formula  was  used : 

Boiling  water gallons. .  5 

Fish-oil  soap pounds. .  2 

Caustic  soda do 2 

Creosote  oil gallons. .  5 

The  caustic  soda,  soap,  and  oil  were  added  in  turn  after  the  water 
started  to  boil,  and  the  mixture  was  forced  through  the  pump  to 
emulsify  it.  Water  (40  gallons)  was  then  added  to  make  50  gallons 
of  wash. 

Plat  7b,  5  per  cent  creosote-oil  emulsion. — This  was  made  in  the 
same  maimer  as  for  plat  7a,  except  that  100  gallons  of  spray  were 
made. 

Plat  8t  commercial  carbolic  emulsion  (distillate). — The  following 
formula  was  used: 

Emulsion gallons. .       5 

Water do 40 

Plat  9,  10  per  cent  crude-oil  emulsion. — This  was  made  with  the 
ingredients  proportioned  as  follows: 

Boiling  water gallons. .  5 

Caustic  soda pound . .  -£ 

Fish-oil  soap '. pounds..  4 

Crude  oil  (12°  to  14°  Baumej gallons. .  5 

The  caustic  soda,  soap,  and  oil  were  added  to  the  water,  in  turn,  as 
soon  as  it  had  started  to  boil.  The  mixture  was  then  forced  through 
the  pump  twice  to  emulsify  it.  Water  (40  gallons)  to  make  50  gal- 
lons of  wash  was  then  added.  The  emulsion  was  not  perfect,  as  some 
free  oil  came  to  the  top. 

Plat  10,  caustic  soda. — The  following  formula  was  used: 

Water gallons. .     50 

Caustic  soda pounds. .       4 


154 


DECIDUOUS   FRUIT   INSECTS  AND  INSECTICIDES. 


Plat  11a,  12  per  cent  crude-oil  emulsion. — The  formula  was  as 
follows : 

1m tiling  water gallons..   10 

Fish-oil  soap pounds. .     2\ 

Lye do \ 

Crude  oil  (16°  to  22°  Baume) gallons..     3 

The  soap  and  lye  were  dissolved  in  the  water,  which  was  then 
placed  in  a  barrel;  22  gallons  of  water  were  then  added  and  the  oil 
slowly  poured  in,  and  the  mixture  was  thoroughly  stirred.  A  very 
good  emulsion  resulted. 

Plat  lib,  12  per  cent  crude-oil  emulsion. — Same  as  for  plat  11a, 
except  that  a  " kerosene  soap"  was  used. 

Plat  lie,  12  per  cent  crude-oil  emulsion. — Same  as  11a,  except  that 
a  14°  Baume  crude  oil  was  used. 

Plat  lid,  12  per  cent  crude-oil  emulsion. — Same  as  11a,  except  that  a 
12°  to  14°  Baume  crude  oil  was  used. 

None  of  the  emulsions  for  plat  11  was  forced  through  the  pumps; 
but,  on  the  other  hand,  no  water  was  added  to  the  mixture  after  the 
oil  had  been  poured  in.  It  seems  to  be  essential,  in  order  to  keep 
free  oil  from  coming  to  the  top,  that  this  be  avoided.  A  good  emulsion 
resulted  in  each  case.  The  difference  in  gravity  did  not  seem  to  make 
much  difference  in  the  emulsions,  but  the  16°  to  22°  Baume,  which 
was  a  "Coalinga  special,"  appeared  to  give  the  best  emulsion.  All 
of  the  crude  oils  used  contained  an  asphalt  base. 

RESULTS. 

The  results  of  the  several  sprays  are  given  in  Table  II. 

Table  II. — Results  of  spraying  for  the  European  pear  scale,  San  Jose,  Cat.,  1908. 


Treatment. 

Date 
sprays 
applied. 

Num- 
ber 
trees 
spray- 
ed. 

First     examination, 
Mar.  3,  1908. 

Plat 
No. 

Num- 
ber 
scales 
exam- 
ined. 

Num- 
ber 
scales 
dead. 

Per- 
cent- 
age 
of 
dead 
scales. 

1 

Lime-sulphur  (homemade) 

Feb.   18 
...do.... 
...do.... 
...do.... 

Feb.   19 
...do 

16 
9 
13 
13 

7 

8 
11 
B 
11 
L3 
L2 
-■ 
6 
6 
8 
6 

1.172 
547 
838 

834 

1,042 
664 

995 

S54 

1.177 
905 

1,000 
51 
581 
280 
285 
364 
174 
424 
780 
689 
480 
632 

85 

2 
3 

4 
6a 

Commercial  Lime-sulphur,  No.  l 

Commercial  lime-sulphur,  No.  2 

Commercial  distillate-oil  emulsion 

9 
69 
30 
34 

56 

34 

7-1 



Commercial  creosote-oil  emulsiorj 

...do.... 

...do 

2(1 
42 

76 

.do 

91 

8 

Commercial  carbolic-distillate  emulsion 

...do 

87 

0 

Cnhlc-nii  emulsion 

...do 

40 

in 

...do 

64 

lid 

Mar.     S 

do 

Lift 
Lie 

lid 

•  to 

do 

I 

...do... 

EUROPEAN   FRUIT  LECAXIUM   AND   PEAR    SCALE.  155 

Table  II. — Results  of  spraying  for  the  European  pear  scale,  Sayi  Jose,  Cal.,  1908 — Con. 


Treatment. 

Second  examina- 
tion. Mar.  21. 1908. 

Remarks. 

Plat 
No. 

NhuJ?-Xum- 

sJales     ber 
^!^  scales 

Per- 
cent- 
age 
of 
dead 
scales. 

Third  examination,  Dec.  17, 
1908. 

i 

Lime-sulphur     (home- 
made). 

Commercial   lime-sul- 
phur. Xo.  1. 

Commercial    lime-sul- 
phur, Xo.  2. 

Commercial    distillate- 
oil  emulsion. 

Distillate  oil   emulsion 

(homemade). 
do 

1,000       828 
492         51 

82 

10 

70 

43 

52 

53 
35 

74 

91 
87 

69 

64 

100 

100 
100 
90 

11 

Many    scales    living;  lichens 

mostly  dead. 
Many    "scales     living;     only 
larger  lichens  dead. 
Do. 

Many  scales  living;  no  lich- 
ens killed. 
Do. 

Do. 

2 

3 
4 

56 

838 

646 

549 

678 
490 

571 

854 
789 

697 

905 

(•) 

(•) 
(«) 

(«) 
736 

581 

2S0 
285 

364 

174 

424 

780 
689 

480 

632 

w 

(») 
(») 

(c) 

84 

Scale     killed     better 
where  there  is  heavy 
incrustation. 

Lichens  not  all  killed . . 

do 

do 

do 

Lichens  all  killed;  bark 
hard  and  injured. 

Lichens  all  killed 

do 

do 

Lichens     all     killed; 

bark  hard. 
do 

6 
7a 

lb 

Commercial  creosote- 
oil  emulsion. 

Creosote-oil    emulsion 

(homemade). 
do 

Many  scales   living;   lichens 

mostly  living. 
Many  scales   living;   lichens 

mostlv  dead. 
Do." 

8 

9 
,0 

Commercial     carbolic- 
distillate  emulsion. 
Crude-oil  emulsion 

Caustic  soda 

Do. 

Most  all  scales  dead;  lichens 

mostly  all  dead. 
Most  all  scales  living;  lichens 

mostlv  all  dead. 

,» 

Crude-oil  emulsion 

do... 

lib 

do 

mostly  all  dead. 
Do. 

lie 

lid 

Check 

do 

do 

do 

Do. 

do 

Do. 

Unspraved 

a  Large  number. 


b  All. 


c  Xearlv  all. 


An  examination  of  the  table  shows  that  at  the  end  of  the  season 
only  the  crude-oil  emulsions  had  proved  adequate  in  killing  all  the 
scales  and  lichens.  Xo  injury  to  the  trees  was  apparent  except  where 
the  caustic  soda  and  creosote-oil  emulsion  were  used. 

SPRAYING    EXPERIMENTS    IN    1909. 

PLAN    OF   WORK   AND    MANNER    OF' APPLICATION. 

A  badly  infested  orchard  other  than  the  one  used  in  1908  was 
selected  and  divided  into  6  different  plats  of  32  trees  each.  Four 
examinations  of  infested  material  were  made  in  the  laboratory  and 
in  the  field  at  intervals  of  three  days,  three  weeks,  six  weeks,  and 
eight  months,  respectively,  after  the  applications.  A  large  number 
of  scales  was  examined  from  each  of  the  six  plats  and  the  check  plat. 

The  applications  were  made  March  1,  1909,  with  a  strong  power 
outfit,  using  two  leads  of  hose  with  12-foot  bamboo  rods  and  single- 
crook  nozzles,  with  J-inch  apertures.  A  pressure  of  200  to  240 
pounds  was  maintained,  and  the  trees  were  given  a  very  thorough 
treatment. 


156  DECIDUOUS  FRUIT  INSECTS  AND  INSECTICIDES. 

SPRATS    1-lD    WD    MKTHOD    OF   PREPARATION. 

Plat  1,  6  per  cent  distillate  oil   {mechanical  mixture). — This  was 

prepared  as  follows: 

Water gallons. .     90 

( Sausl  ic  Boda pounds. .      2 

Distillate  oil  (28°  Baume) gallons. .       6 

The  water  was  poured  into  the  tank;  then  the  caustic  soda  was 
added  to  soften  the  water,  and  the  oil  slowly  poured  in  while  the 
water  was  being  violently  agitated.  The  mixture  was  applied 
immediately. 

Plat  2 j  caustic  soda. — The  formula  was  as  follows: 

Water gallons. .   100 

Caustic  soda pounds. .     16 

Plat  3,  crude-oil  emulsion. — This  was  prepared  as  follows: 

Water gallons. .  86 

Fish-oil  soap pounds. .  10 

Lye do 2 

(  rude  oil  (16°  to  22°  Baume) gallons. .  1 2 

About  20  gallons  of  the  water  were  heated,  and  when  this  began  to 
boil  the  dissolved  soap  and  then  the  lye  were  added.  This  mixture 
was  then  removed  to  the  tank,  and  the  rest  of  the  water  (66  gallons) 
added,  making  86  gallons  in  all.  The  spray  pump  engine  was  then 
started  and  the  crude  oil  slowly  poured  into  the  tank,  the  mixture 
being  violently  agitated  by  the  tank  agitator.  A  perfect  emulsion 
resulted. 

Plat  4,  commercial  lime-sulphur  solution,  No.  1. — The  formula  was 
as  follows: 

Water gallons. .   100 

Commercial  lime-sulphur ...do 11 

Plat  5,  borax. — The  formula  was  as  follows: 

Water gallons. .  100 

Borax pounds..     20 

The  borax  was  dissolved  in  30  gallons  of  hot  water  and  poured  into 
the  tank,  and  the  rest  of  the  water  added. 

Plat  6,  well-cooked  lime-sulphur  wash. — The  proportions  of  ingredi- 
ents were  as  follows: 

Lime pounds..     30 

Sulphur do....     30 

Water gallons. .   100 

This  wash  was  made  in  the  same  manner  as   previously  described. 


EUROPEAN   FRUIT  LECANIUM  AXD   PEAR    SCALE.  157 

The  results  of  tests  in  1909  are  given  in  Table  III. 
Table    III. — Results  of  spraying  for  the  European  pear  scale,  San  Jose,   Cal.,  1909. 


First  examina-   Second  examina- 

© 

tion,  Mar. 

3-4,        tion 

.  Mar. 

20, 

Treatment. 

Date 
spravs 

S 

— 

w 

09 

1909. 

1909. 

a; 

J 

^ 

3 

'B  — 

Remarks. 

applied. 

— 

u 

U 

^ 

*5 

>-— ' 

frs 

Z 

.a 

i 

g  9 

fl 

S  -J 

63 

d 

-  - 

r 

r  g 

3  -_ 

3 

-  M 

fc 

fe 

z 

z 

- 

z 

z 

1     Distillate-oil    mechan- 

Mar.    1 

32 

620 

516 

83 

498 

380 

78 

Lichens  mostly  alive. 

ical  mixture. 

2     Caustic  soda 

...do.... 

32 

706     534 

75 

844 

749 

88 

Do. 

3     Crude-oil  emulsion 

...do.... 

32 

344     297 

86 

599 

393 

65 

Lichens  all  dead. 

4     Commercial     lime-sul- 

...do.... 

32 

950 

846 

89 

709 

627 

88 

Lichens  mostly  dead. 

phur,  Xo.  1. 

5  1  Borax 

...do.... 

32 

407 

361 

88 

£029 

1,003 

97 

Do. 

6     Homemade      lime-sul- 

...do.... 

32 

371 

275 

74 

673 

504 

74 

Lichens  nearly  all  alive. 

phur. 

7 

Check 

941 

.541 

56 

685 

341 

49 

Lichens  flourishing. 

Treatment. 

Third  examina-      Fourth  examina- 
tion, Apr.  16, 1909.   tion.  Nov.  20, 1909. 

6 

z 

•r. 

8  J 
11 
z 

- 

1*6 

-  - 

a 
Z 

1i 

BO 

- 

11 

-  r; 
1  X 
3   I 

z 

jl 

z 

- 

i   "3 

Remarks. 

i 

2 

Distillate-oil    mechan- 
ical mixture. 
Caustic  soda 

805 

637 
648 
536 

640 
652 

372 

789 

449 
613 

411 

609 

514 

133 

98 

70 
94 
76 

95 
79 

35 

759 

455 
207 
659 

452 

1.1* 

939 

757 

449 
207 
624 

449 
811 

96 

100 

98 
100 
93 

99 
70 

10 

Lichens  mostly  dead:  bark  soft. 

3 

4 

5 

Crude-oil  emulsion 

Commercial     lime-sul- 
phur, Xo.  1. 
Borax 

Lichens  mostly  dead;  bark  soft. 
Lichens  mostly  dead;  bark  slight  ly 

hardened. 
Lichens  mostly  dead:  bark  hard. 

6 

7 

Homemade      lime-sul- 
phur. 
Check 

Lichens  mostly  dead;  bark  slightly 

hardened. 
Lichens  flourishing. 

RESULTS. 


An  examination  of  Table  III  shows  that  all  of  the  sprays  with  the 
exception  of  the  commercial  lime-sulphur  solution  Xo.  1  and  the  well- 
cooked  lime-sulphur  washes  proved  very  successful  in  killing  the  scale. 
All  of  them  killed  most  of  the  lichens.  The  caustic-soda  and  borax 
treatments  injured  the  trees  to  a  certain  extent  and  hardened  the 
bark.  In  the  case  of  the  trees  treated  with  distillate-oil  emulsion  and 
crude-oil  emulsion  the  bark  was  normal  and  in  good  condition. 

As  noted  previously,  on  the  apricots  the  distillate-oil  sprays  as  well 
as  those  from  crude  oil  seemed  to  possess  distinct  fungicidal  proper- 
ties, as  the  foliage  was  as  dark  and  healthy  on  these  plats  and  remained 
on  the  trees  as  long  as  on  the  plats  sprayed  with  commercial  and 
cooked  lime-sulphur  washes. 

A  comparison  of  the  results  of  1908  and  1909  shows  much  in  favor 
of  the  latter  year,  which  should  be  attributed  to  the  better  method  of 
application  and  of  making  the  sprays.     It  appears  essential  for  good 


158  DECIDUOUS    FBUTT    [NSEGTS   AND    INSECTICIDES. 

results  to  use  a  power  outfit  at  a  high  pressure  and  a  coarse  drenching 
spray  to  penetrate  the  lichens  and  the  heavy  scale  incrustation.  A 
power  sprayer  is  especially  useful  in  applying  distillate-oil  emulsion, 
crude-oil  emulsion,  and  mechanical  mixtures  of  either,  as  a  hand  outfit 
does  not  give  sufficient  agitation  for  a  perfect  emulsion. 

The  writer  recently  noticed  several  prune  orchards  which  had  been 
sprayed  with  a  commercial  distillate  spray  and  caustic  soda  at  4  per 
cent  strength;  they  were  well  cleaned  of  the  scales  and  lichens. 

COST  OF  SPRAYING. 

Table  IV  shows  the  comparative  cost  of  materials  of  the  most  im- 
portant and  efficient  treatments.  To  get  the  total  cost  of  spraying 
it  will  be  necessary  merely  to  add  the  cost  of  the  labor,  which  is  vari- 
able and  was  therefore  not  included.  Usually  3  men  and  a  team 
are  required  for  spraying  with  a  hand  pump  and  the  same  number 
with  a  power  outfit,  adding  an  additional  man  and  team  where  a 
supply  wagon  is  used. 

The  number  of  trees  that  can  be  sprayed  in  a  day  is  variable, 
depending  upon  the  size  of  the  trees,  the  availability  of  the  water,  and 
the  efficiency  of  the  labor.  With  medium-sized  prune  trees,  from  800 
to  1,000  trees  is  considered  a  good  day's  work  with  a  power  outfit 
and  a  supply  tank. 

Below  is  shown  what  the  ingredients  of  the  spray  mixtures  wrould 
cost  the  fruit  growrer  in  the  vicinity  of  San  Jose  in  barrel  lots: 

Lime  (unslaked) per  barrel . .  SI .  75 

Sulphur  (flour) per  100  pounds. .  2.  65 

Caustic  soda,  in  120-pound  cases per  pound . .  .  05£ 

Borax,  in  12-pound  cases 1 .  40 

Lye,  in  48-pound  cases 3.  25 

Pish  oil,  in  barrel  lots per  gallon. .  .  35 

Crude  oil    11'  to  24°  Baum£),  in  110-gallon  drums 3.  00 

Distillate  oil  (28°  Baume),  in  110-gallon  drums per  gallon. .  .  07-.  09 

Commercial  lime-sulphur  solution per  barrel. .  «  10.  00 

Commercial  distillate-oil  emulsion do a  7.  50 

Commercial  distillate  emulsion  and  caustic  soda do a  9.  95 

A  good  fish-oil  soap  can  be  made  at  the  following  cost: 

Lye,  2  pounds *<>.  i:;:> i 

Fish  nil,  i\  gallons 5250 

Water,  (i  gallons. 

This  makes  $0.6604  for  40  pounds  of  soap,  of  $0.0165  per  pound. 
The  concentrated  distillate-oil  emulsion  (55  per  cent )  will  cost: 

Hot  water,   12  gallons. 

Fish  "il  soap,  :'.<»  pounds $0.  -}!'"» 

Distillate  <.il  (28    Baume*  .  20 gallons 1.400 

T,  .h. I 1.  895 

This  makes  $1,895  for  •".<>  gallons,  or  $().().Y_>()  per  gallon. 

"  About. 


EUROPEAN   FRUIT  LECANIUM   AND   PEAR    SCALE.  159 

Table  IV. — Comparative  cost  of  spray  material-;. 


Formula. 


Treatment. 


Article. 


Quantity. 


I    Cost  of     Cost  per   Cost  per 
ingredi-     100  gal-     diluted 
ents.  Ions.       gallon. 


per  cent  distillate 
oil  (mechanical 
mixture). 

per  cent  distillate- 
oil  emulsion. 


5  per  cent  distillate- 
oil  emulsion  and 
caustic  soda. 

4  per  cent  commercial 
distillate-oil  emul- 
sion. 

4  per  cent  commercial 
distillate-oil  emul- 
sion and  caustic 
soda. 

12  per  cent  crude-oil 
emulsion. 


Resin-soda  wash. 


Commercial  lime-sul- 
phur No.  1  (1-8). 

Home-made  lime-sul- 
phur. 


Caustic  soda. 
Borax 


{Oil 6  gallons.. 
Caustic  soda 2  pounds. 
Water I  94  gallons. 


(■Concentrated  emul- 
|     sion. 

Caustic  soda 

IWater 

[Concentrated  emul- 
)     sion. 

Caustic  soda 

[Water 

f  Emulsion 
Water 


I  Emulsion. 
|  Water 


(Oil 

I  Soap 

Lve 

[Water 

(Resin 
Caustic  soda 
Fish  oil 
Water 

{Concentrated  solu- 
tion. 
Water 

I  Lime 
Sulphur 
Water 

iCausticsoda 

\Water 

IBorax 

IWater 


$0.42 
.11 


11  gallons. . . 

2  pounds 

89  gallons. . . 

9  gallons 

10  pounds. . . 
91  gallons 

Of  gallons. . . 
92§  gallons . . 

6|  gallons. . . 
92§  gallons . . 

12  gallons. . . 

10  pounds. . . 

2  pounds 

88  gallons. . . 
20  pounds... 
6  pounds 

3  gallons 

100  gallons . . 

11  gallons. 


;;:l 


5786 
,11 


.  4734 


S-i.-.i 


'}•' 


1.023 


$0.00.53 


1.00 


1.326 


.  32C4 
.0875 
.1354 


.33 
.  1311 


.  5493 


1.011 


}     2.20 


88  gallons. 

40  pounds 

30  pounds 

100  gallons 

12  pounds. . .  1 

100  gallons . .  j 

20  pounds. . .  \    0  m 

100  gallons..  /    "*- 


.35 
.795 


66 


2.20 


.66 
2.32 


.0102 


.ill 


,0132 


.0054 


.0101 


.022 


.0066 
.  0232 


"°Sr  P-tree 
Cpnme).    gg* 


$0.0212 


.0275 


.0406 


$0.0265 


.0511 


.0528 


.0219 


.0404 


.058 

.0264 
.0928 


.  0274 


.0505 


.0725 

.033 
.116 


SUMMARY. 

Distillate-oil  emulsion  at  5  per  cent  and  6  per  cent  strengths,  with 
and  without  caustic  soda;  crude-oil  emulsion  at  12  per  cent  strength: 
and  resin-soda  wash  are  effective  in  controlling  the  European  fruit 
Lecanium  and  in  cleaning  up  the  trees  from  lichens  and  do  not  injure 
the  trees  when  applied  as  a  winter  treatment. 

Distillate-oil  emulsion  at  5  per  cent  and  6  per  cent  strengths,  with 
and  without  caustic  soda;  distillate  oil  at  6  per  cent  strength  (mechan- 
ical mixture);  and  crude-oil  emulsion  at  12  per  cent  strength  are 
effective  in  controlling  the  European  pear  scale,  destroy  the  lichens, 
and  do  not  injure  the  trees  when  applied  as  a  winter  treatment. 

Caustic-soda  and  creosote-oil  emulsion  sprays  control  both  of  these 
scales  and  destroy  the  lichens,  but  are  injurious  to  the  tree. 

Lime-sulphur  and  borax  sprays  are  not  so  efficient  in  controlling 
these  scales,  especially  the  European  fruit  Lecanium,  as  are  the 
distillate-oil  and  crude-oil  emulsions,  and  borax  acts  on  the  trees  in 
the  same  way  as  does  caustic  soda. 

Distillate-oil  and  crude-oil  emulsions  appear  to  have  distinct  fungi- 
cidal properties  aside  from  their  insecticidal  value. 


160  DECIDUOUS    PBUIT   INSECTS   AND    INSECTICIDES. 

Distillate-oil  emulsions  at  6  per  cent  Btrength  and  crude-oil  emul- 
sion at    12  per  cent  Btrength,  measured  by  their  efficiency  against 

scales  and  lichen-,  convenience  of  preparation  and  application,  and 
cost,  are  the  sprays  besl  adapted  for  the  European  fruit  Lecanium 

and  the  European  pear  scale. 

The  6  per  cent  distillate-oil  emulsion  will  cost  about  2\  cents  for 
each  prune  tree  and  '.\\  cents  for  each  apricot  tree. 

The  12  per  cent  crude-oil  emulsion  will  cost  about  2  cents  for  each 
prune  tree  and  2\  cents  for  each  apricot  tree. 

All  sprays,  to  insure  the  best  results,  should  be  applied  with  a 
power  outfit  at  a  high  pressure  (180  to  200  pounds).  A  coarse, 
drenching  spray  applied  with  crook  nozzles  is  preferable,  and  Feb- 
ruary i^  the  hot   month  in  which  to  spray. 


INDEX 


Page. 

Apple  bitter  rot,  Bordeaux  mixture  as  remedy 115-116, 118, 131, 146 

calyx  cup  in  relation  to  spraying  for  codling  moth 113-115 

crab,  food  plant  of  Coleophora  fietcherella 36 

food  plant  of  codling  moth 1-32,  71-111 

Coleophora  fietcherella 36 

Enarmonia  prunivora 30,  46-47 

Epinotia  pyricolana 30, 46 

fruit  blotch,  Bordeaux  mixture  as  remedy 115-116, 118, 146 

leaf-spot  affections,  Bordeaux  mixture  as  remedy 115-116, 146 

scab,  Bordeaux  mixture  as  remedy 115-116, 119, 139, 146 

worm,  lesser.     (See  Enarmonia  prunivora.) 
Arsenate  of  lead  against  codling  moth  and  plum  curculio,  one-spray  method 

versus  usual  schedule  of  applications 116-146 

and  Bordeaux  mixture  against  codling  moth  and  plum  cur- 
culio, one-spray  method  versus  usual  schedule  of  applica- 
tions    116-146 

Arsenicals  against  cigar  case-bearer 41 

Ascogaster  carpocapsse,  parasite  of  codling  moth 110 

Aspidiotus  perniciosus,  resemblance  of  Epidiaspis  pyrieola  thereto 151 

Black-leaf  extract.     (See  Tobacco  extract.) 

Borax,  cost  in  barrel  lots,  San  Jose,  Cal 158 

spray  against  European  fruit  Lecanium 150-151, 159 

wash,  cost  per  gallon  and  per  apricot  or  prune  tree 159 

Bordeaux  mixture  against  fungous  diseases  of  apple 116, 146 

and  arsenate  of  lead  against  codling  moth  and  plum  curculio, 

one-spray  method  versus  usual  schedule  of  applications.  116-146 
Braucher,  R.  W.,  E.  L.  Jenne,  E.  W.  Scott,  and  A.  L.  Quaintance,  paper,  '"The 
one-spray  method  in  the  control  of  the  codling  moth  and  the  plum  curculio"  113-146 

Calyx  cup  of  apple  in  relation  to  spraying  for  codling  moth 113-115 

Camponotus  pennsylvanicus,  enemy  of  codling  moth 110 

Carbolic  acid  and  oil  emulsions  against  pear  thrips,  injurious  to  trees 64 

emulsion  (distillate)  against  European  pear  scale 153, 154-155 

Carpocapsa  pomonella.     (See  Codling  moth.) 

putaminana=Y&riety  of  Carpocapsa  pomonella 69 

feeding  on  French  walnuts 69 

Case-bearer,  cigar.     (See  Coleophora  fietcherella.) 

Caustic  soda  against  European  fruit  Lecanium 149-151, 159 

pear  scale 153, 154-155, 156-158, 159 

and  distillate-oil  emulsion  against  Etiropean  fruit  Lecanium .    149-151, 159 
commercial,    cost    in    barrel    lots,    San 

Jose,  Cal 158 

4  per  cent,  cost  per  gallon 
and  per  apricot  or  prune 

tree 159 

5  per  cent,  cost  per  gallon 
and  per  apricot  or  prune 

tree 159 

161 


162  DECIDUOUS   FRUIT   INSECTS   AND   INSECTICIDES. 

Page. 

Caustic  soda,  coal  in  barrel  Lots,  San  Jose,  Cal 158 

wash,  cost  per  gallon  and  per  apricot  or  prune  tree 159 

Ghalcidid  parasite  of  codling  moth 30 

Chestnut,  reported  food  plant  of  Carpocapsa  pomonella 67 

( 'hrysopa  oculatu,  enemy  of  Colcophora  Jletcherella 41 

Cigar  case-bearer.     (See  Colcophora  Jletcherella.) 

Codling  moth,  abundance  in  apples  compared  with  Enarmonia  prunivora 46-47 

control  on  French  walnuts 70 

in  northwestern  Pennsylvania: 

Band  records  <»i  1907  and  1908 102-104 

1909 95-98 

Control  with  poison  sprays Ill 

First  brood  eggs,  period  of  incubation 80 

larvae,  larval  life  in  cocoon 85 

number  in  each  apple 81 

percentages  of  those  transforming  and  wintering 84 

period  of  feeding  of  transforming  larvae , . . .  81-83 

wintering  larvae 81-83 

time  of  hatching 81 

maturing  of  transforming  larvae 84 

wintering  larvae 84 

moths,  length  of  life  of  individual  males  and  females 88 

o viposition  period 87-88 

time  of  emergence,  1907  and  1908 100-102 

1909 87 

pupae,  length  of  stage 85-86 

time  of  pupation 85 

generation 80-91 

Insect  enemies 110 

Life  cycle  of  first  generation 88-91 

history  studies  for  1907,  1908,  and  1909,  comparison 108-109 

Overwintering  larvae 72-73 

Review  of  life-history  work  of  1909 98 

Seasonal-history  studies  of  1907  and  1908 98-104 

1909 72-98 

Second  brood  eggs,  incubation  period 91-93 

larvae,  feeding  period 93-95 

immature  specimens  at  hibernation  time 95 

time  of  hatching 93 

leaving  fruit  for  wintering 95 

generation 91-95 

Source  of  roaring  material,  1907  and  190S 98 

1909 72 

Spring  brood  moths,  length  of  life 79 

oviposition  period 77-79 

time  during  day  when  they  emerge 77 

of  emergence,  L907  and  1908 100 

1909 74-75 

vs.  time  larva  leave  fruit  preced- 
ing year 75-77 

pupss,  length  of  stage 73-74 

time  of  pupation 73 

Summary 110-111 

Weather  records  for  1907,  1908,  and  1909 104-108 


INDEX.  163 

Codling  moth  in  the  Ozarks:  Page. 

Band  records 23-26 

Conclusions 31 

Emergence  of  moths 26-27 

First-brood  eggs,  fertility 7 

incubation  period 7-8 

oviposition  period 6-7 

place 7 

larvae,  larval  life  in  cocoon 9 

maturing 9 

period  in  fruit 9 

of  hatching 8-9 

moths 10-11 

pupae 10 

generation 6-11 

Larvae  in  peaches 28 

on  foliage  of  apple 27-28 

Length  of  life  cycle  of  first  generation 11 

second  generation 15-17 

Miscellaneous  observations 23-30 

Molts,  number 29 

Moths,  emergence 26-27 

Natural  enemies .' 29-30 

Numerous  larvae  in  one  apple 28 

Percentage  of  fruit  infested 30 

Review  of  rearing  work  of  season  of  1908 ."*. 20-23 

Seasonal  history 1-20,  32 

Second-brood  eggs 11 

larvae,  larval  life  in  cocoon 13 

maturing 12 

period  in  fruit 12-13 

of  hatching 12 

moths 15 

pupae 13-14 

generation 11-17 

Spring-brood  moths,  duration  of  emergence 4-5 

life  of  moth 5-6 

pupae,  duration 1-2 

length  of  stage 2-A 

Third-brood  eggs 17-18 

larvae 18-19 

generation 17-19 

in  1907 22-23 

Wintering  larvae 19-20 

Codling  moth,  nut-feeding  habits 67-70 

one-spray  method  in  control,  conclusions 146 

experiments  in  Arkansas 116-125 

Michigan 137-143 

Virginia 130-133, 

134-136 

summary,  statement  of  results..  145-146 

seasonal  history  on  French  walnuts 68-69 


164  DECIDUOUS    FRUIT    ENSECTS   AND   INSECTICIDES. 

Page. 

CoU  ophora  fletchi  rella 33-44 

adult  or  moth,  description 38 

bibliography 42-44 

control  methods 41 

description 37-38 

distribution 35-36 

description 37 

enemies 41 

Food  plants 36 

history 33-35 

larva  and  its  cases,  description 37-38 

life  cycle 40 

pupa,  description 38 

seasonal  history 39-40 

sp..  near fletcherella,  on  sugar  beet 35 

t  bnotrachelus  ru  nuphar.    (See  Plum  curculio.) 

Crataegus,  food  plant  of  Coleophora  fletcherella 30 

Enarmonia  prunivora A  v 

(  v,  mastogaster  bicolor,  enemy  of  codling  moth . 30 

lineolata,  enemy  of  codling  moth 110 

Creosote  and  oil  emulsion  against  European  pear  scale 153, 154-155, 159 

emulsions  against'  pear  thrips,  injurious  to  trees 64 

Crude  oil,  cost  in  barrel  lots,  San  Jose,  Cal. *  . . .       158 

emulsion  against  European  fruit  Lecanium 149-151,  159, 160 

pear  scale . .   153, 154-155.  150-158, 159-160 

12  per  cent,  cost  per  gallon  and  per  apricot  and  prune  tree.       159 

<  'ri/ptarcha  ampla  on  trees  banded  for  codling  moth 110 

Cultural  methods  against  pear  thrips 60-63 

Curculio,  plum.     (See  Plum  curculio.) 
Distillate  oil  (see  also  Kerosene) . 

and  caustic  soda,  6  per  cent  mechanical  mixture,  against  Euro- 
pean pear 
scale..  156,157,159 
cost  per  gallon 
and  per  apri- 
cot or  prune 

tree 159 

cost  in  barrel  lots,  San  Jose,  Cal 158 

emulsion  against  European  fruit  Lecanium 148-151, 159, 160 

pear  scale  152-153, 154-155, 156-158, 159-160 
a  ml  <  a  ust  ic  soda  against  European  fruit  Lecanium.  149-151, 159 
commercial,  cost   in    barrel    lots,  San 

Jose,  Cal 158 

4  per  cent,  cost  per  gallon 
and  per  apricot  or  prune 

tree 159 

5  per  cent,  cost  per  gallon 
and  per  apricot  or  prune 

tree 159 

tobacco  extract  against  pear  thrips 63-65 

commercial,  cost  in  barrel  lots,  San  Jose,  Cal 158 

concentrated,  cost  per  gallon 158 


INDEX.  165 

Page. 
Distillate  oil  emulsion,  4  per  cent  commercial,  cost  per  gallon  and  per  apricot  or 

prune  tree 159 

6  per  cent,  cost  per  gallon  and  per  apricot  or  prune  tree. .       159 

Dromius  piceus,  enemy  of  codling  moth 110 

Enarmonia  prunivora 45-50 

abundance  in  apples  compared  with  codling  m©th 46-47 

control  measures 50 

description  of  egg 50 

duration  of  egg  stage 48-49 

larval  stage 49 

in  cocoon  before  pupating 49 

pupal  stage 49-50 

habits '. 47^8 

infesting  apples 30 

life  cycle 48-50 

one-spray  method  in  control 128-129 

parasites 50 

seasonal  history ■ 47-48 

Epidiaspis  pyricola,  appearance 151-152 

cost  of  spraying  therefor 158-159 

injury,  extent 152 

tests  of  sprays  in  control 151-158 

summary 159-160 

Epinotia  pyricolana  infesting  apples 30.  46 

Euthrips  occidentalis  in  pear  and  cherry  blossoms 52 

pyri 51-66 

adult,  seasonal  history 60 

appearance  of  adults  from  soil  in  spring 55-56 

character  of  injury 52-55 

distribution 51-52 

egg 57 

habits 55-60 

injury  by  adults  feeding 52-55 

ovipositing 55 

larvae 55 

larva,  description,  habits,  seasonal  history 58-59 

methods  of  treatment 60-66 

migration  of  adults 57 

opposition 57 

pupa,  seasonal  history 59-60 

summary , 66 

tritici  in  pear  blossoms 52 

Fertilizers  ineffective  in  killing  pear  thrips 65 

Fish  oil,  cost  in  barrel  lots,  San  Jose,  Cal 158 

soap,  cost  of  ingredients  per  pound 158 

Formica  subsericea,  enemy  of  codling  moth 110 

Foster,  S.  W.,  paper,  "On  the  Nut-Feeding  Habits  of  the  Codling  Moth  " 67-70 

and  P.  R.  Jones,  paper,  "Additional  Observations  on  the  Lesser 

Apple  Worm  (Enarmonia  prunivora  Walsh) " 45-50 

Fungous  diseases  of  apple,  Bordeaux  mixture  or  lime-sulphur  wash  as  remedy .  116, 146 

Fungus,  sooty,  on  honeydew  from  European  fruit  Lecanium 147 

Galerita  janus,  enemy  of  codling  moth 110 


166  DECIDUOUS  FRUIT  INSECTS   AND    INSECTICIDES. 

Page. 

Geophilus  ruberu,  enemy  of  codling  moth 110 

Habrocytus  sp.,  parasite  of  Coleophora  fletcherella 41 

Bammar,  A.  (I.,  paper,  "Life  History  of  the  Codling  Moth  in  Northwestern 

Pennsy]  vania  " 71-111 

"The  Cigar  Case-bearer   (Coleophora  fletcherella   Fer- 

nald)" 33-34 

Hickory  nut,  larva  of  Carpocapsa  pomonella  hibernating  therein 67 

Hymenortu  sp.,  on  trees  banded  for  codling  moth 110 

Irrigation  ineffective  against  pear  thrips 66 

Jenne,  E.  L.,  paper,  "The  Codling  Moth  in  the  Ozarks" 1-32 

E.  W.  Scott,  R.  W.  Braucher,  and  A.  L.  Quaintance,  paper,  "The 
One-spray  Method  in  the  Control  of  the  Codling  Moth  and  the 

Plum  Curculio" 113-146 

Jones,  P.  R.,  paper,  "Tests  of  Sprays  against  the  European  Pear  Scale  " 147-160 

and  S.  W.  Foster,  paper,  "Additional  Observations  on  the  Lesser 

Apple  Worm  (Enarmonia  prunivora  Walsh) " 45-50 

Kerosene  (see  also  Distillate  oil). 

emulsion  against  cigar  case-bearer 34,  41 

Ladybird  enemies  of  Coleophora  fletcherella 41 

J j can ium  armeniacum=Lecanium  corni 147 

corni,  appearance  of  insect 148 

cost  of  spraying  therefor 158-159 

tests  of  sprays  in  control 148-151 

-      summary 1 59-160 

European  fruit.     (See  Lecanium  corni.) 

Lichens,  effect  of  sprays  on  growth  on  deciduous  fruit  trees 148, 

150. 151. 152, 155, 157-160 

Lime,  cost  in  barrel  lots,  San  Jose,  Cal 158 

sulphur  solution,  commercial,  against  European  fruit  Lecanium  . .  150-151, 159 

pear  scale 152, 

154-155, 156-157 

cost  in  barrel  lots,  San  Jose,  Cal 158 

ineffective  against  pear  thrips! 63-64 

wash  against  European  pear  scale 152, 154-155, 156-157, 159 

fungous  diseases  of  apple 116, 146 

commercial  No.  1,  cost  per  gallon  and  per  apricot  or  prune 

tree 159 

home-made,  cost  per  gallon  and  per  apricot  or  prune  tree. .       159 

Lye,  cost  in  barrel  lots,  San  Jose,  Cal 158 

Melanotics  flssilis  on  trees  banded  for  codling  moth 110 

Microtias  laticinctus,  parasite  of  Coleophora  fletcherella .* 34.  41 

Mirax  grapholitha  .  parasite  of  Enarmonia  prunivora 50 

Mile  enemy  of  Coleophora  fletcherella 41 

Moulton,    Dudley,  paper,   "The  Pear  Thrips  and    its  Control   (Euthripa  p>/ri 

I  taniel) " 51  66 

Myceto6horet  fraUrna  on  trees  banded  for  codling  moth 110 

Myrmica  lobicOrnit,  enemy  of  codling  moth 1 10 

Oil.    (Set  Distillate  oil  and  Kerosene.) 

Pane  green  against  cigar  vase-bearer 34,41 

Peach,  food  plant  of  Codling  moth  (  ( 'arpoca  psa  pomQTU JIa) 28,67 

food  plant  <>!"  <  'oUophorQ  jit  Ichcn  lla 36 

.  European.    (See  Epiduupis  pyricola.) 

thru  i   Eutkript  pyri.) 


INDEX.  167 

Page. 

Pimpla  annulipes,  parasite  of  codling  moth 30 

Platynus  obsoletus,  enemy  of  codling  mo^th 110 

Plowing.     (See  Cultural  methods.) 

Plum  curculio,  one-spray  method  in  control,  conclusions 146 

experiments  in  Arkansas 126-129 

Michigan 143-145 

Virginia...  133-134,137 
summary  statement  of  results . .  145-146 

food  plant  of  Carpocapsa  pomonella 67 

Coleophora  fletcherella 36 

Quaintance,  A.  L.,  E.  L.  Jenne,  E.  W.  Scott,  and  R.  W.  Braucher,  paper, 
"The  One-spray  Method  in  the  Control  of  the  Codling  Moth  and  the  Plum 

Curculio" 113-146 

Quince,  food  plant  of  Coleophora  fletcherella 36 

Resin-soda  wash  against  European  fruit  Lecanium 150-151, 159 

cost  per  gallon  and  per  apricot  or  prune  tree 159 

Scale,  brown  apricot.     (See  Lecanium  corni.) 

European  pear.     (See  Epidiaspis  pyricola.) 
San  Jose.     (See  Aspidiotus  perniciosus .) 
Scott,  E.  W.,  E.  L.  Jenne,  R.  W.  Braucher,  and  A.  L.  Quaintance,  paper, 
"The  One-spray  Method  in  the  Control  of  the  Codling  Moth  and  the  Plum 

Curculio" 113-146 

Soda-resin  wash  against  European  fruit  Lecanium 150-151, 159 

cost  per  gallon  and  per  apricot  or  prune  tree 159 

Solenopsis  validiusculus,  enemy  of  codling  moth 30 

Sugar  beet,  food  plant  of  species  similar  to  Coleophora  fletcherella 35 

Sulphur  (flour),  cost  in  barrel  lots,  San  Jose,  Cal 158 

Tachinophyto  sp. ?,  parasite  of  codling  moth 30 

Tenebrioides  corticalis,  enemy  of  codling  moth 110 

Tenebrio  tenebrioides  on  trees  banded  for  codling  moth 110 

"Thrip,"  colloquial  and  incorrect  name  for  thrips 52 

"Thrips,"  colloquial  name  for  vine  leafhopper  ( Typhlocyba  comes) 52 

Thrips,  pear.     (See  Euthrips  pyri.) 

Tobacco  extract  and  distillate-oil  emulsion  against  pear  thrips 63-65 

Trombidium  sp.,  enemy  of  codling  moth 29-30 

Typhlocyba  comes,  the  vine  leafhopper,  wrongly  called  "thrips " 52 

Walnut,  French,  food  plant  of  Carpocapsa  pomonella 67-70 

putaminana 69 

o 

30490°— Bull.  80—12 12 


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